User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.11) Gecko/20101012 Firefox/3.6.11 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.11) Gecko/20101013 Thunderbird/3.1.5 This worked, but as I'm composing an email in html, I frequently have occasion to move the cursor back into the body of the text to alter something. After I do that, I then move the cursor back to the end of what I'm composing but still above my signature line, and the font has gone back to "variable width", or Arial which I loath. It does this to me every time too. Reproducible: Always Steps to Reproduce: 1. Change the default composition font to Times New Roman: Tools/Options/Composition/General tab/HTML/ 2. Start composing a message in HTML 3. Move the cursor into the body of the message and alter something. 4. Move the cursor back to the end of the message to the previous insertion point at the end of the last line. Actual Results: I see the font change from Times back to "variable width". Expected Results: The font should remain to what I changed the default font to, in other words, Times New Roman. The font should remain to what I changed the default font to, in other words, Times New Roman. I've seen other problems related to the default font but as far as I know, nobody has mentioned this specific bug.

Forget the very first clause "This worked, but as". That was an editing error on my part and shouldn't have been included in my comments about this bug. In other words, instead of reading: "This worked, but as I'm composing an email in html, I frequently have occasion to move the cursor back into the body of the text to alter something." it should say: "As I'm composing an email in html, I frequently have occasion to move the cursor back into the body of the text to alter something."

Version info: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20101103 Lightning/1.0b2 Thunderbird/3.1.3 I can confirm this behavior in Thunderbird 3.1.3, as well. And, it doesn't seem limited to the windows platforms. However, the behavior seems different between starting a fresh email and responding to one. I have set the default font to "Times", size: "Medium" under Edit > Preferences > Composition > General > HTML. And, if I write a response email with any cursor change via mouse or arrow-keys, it will change the font to "Variable Width" at the end of the area of the Message Body that hasn't explicitly been set as "Times" (e.g. Hit "End" at the last line and it reverts to Variable Width.) Worse yet, when going back to change something within a line I was writing, if I hit the "End" key to get to the end of the line to continue what I was writing, it will change the font to "Variable Width". With a brand-new email, it seems that, in Linux at least, highlighting Body Text with arrow-keys seems to set off the reversion back to "Variable Width". Reproducible: Always Steps to reproduce: 1. With Thunderbird open, click "Write" to open a new email message window. 2. Write a few lines of text. For this example, you can write "asdf"<Enter><Enter>"asdf"<Enter>. 3. Hold the Shift key and hit Cursor-Up key four times, and watch the Font pulldown menu shift from Times to Variable Width to Times to Variable Width. Actual Results: The font will change at each press of the Cursor-Up key between Times and Variable Width. Expected Results: The font remains the font that was originally set. I hope this sheds some light on what the underlying cause might be. If you have any questions or need further information, feel free to email me.

I also see this in 3.1.6. Ironically, I also use Times New Roman.

I have the same issue on a Windows 7 Ultimate x64 with Thunderbird 10.0.7esr. This occurs only when i use a signature. It doesnt matter if the signature is HTML or Plain Text.

Here is another version of reproduction: 1. Configure a non-default font (size) in TB (in my case: "Helvetica Arial", size "small") 2. Click on the "Reply" button of a received e-mail 3. Start writing a response 4. Click on the "Reply" button of a received e-mail (same as above or another one) 5. Move the cursor to any location within the copy of the responded e-mail (i.e. a line other than the first line in the body, where the cursor is automatically positioned) and move the cursor back 6. Start writing a response2. Click on the "Reply" button of a received e-mail 3. Start writing a response2. Click on the "Reply" button of a received e-mail 3. Start writing a response Observed behavior: 2.1 Response composition window gets opened, with the automatically added line "On [date] wrote [name]:" being in the default font, instead of the one configured (NOK, but not very important) 2.2 Cursor gets positioned in the first line of the e-mail body, ready for typing the response. (OK) 3. The response will be written in the configured font (OK) 4. (Same as 2) 6. The response will be written in the default TB font, instead of the one configured (NOK) The same erroneous behavior also occurs sometimes when the above step 5 is done in the middle of the writing an e-mail. I.e., the font for continuation of the writing after brining the cursor back will be the TB default, instead of the configured one. To work around, one needs to simply delete a character written before moving the cursor and re-type it. That will bring the font back to the one used for that deleted character and one can continue typing with the same font. ------------------------------------ There seems to be a long list of bugs related to the seemingly same issue: https://bugzilla.mozilla.org/show_bug.cgi?id=645136 https://bugzilla.mozilla.org/show_bug.cgi?id=203810 https://bugzilla.mozilla.org/show_bug.cgi?id=675032 https://bugzilla.mozilla.org/show_bug.cgi?id=793527 https://bugzilla.mozilla.org/show_bug.cgi?id=581110 https://bugzilla.mozilla.org/show_bug.cgi?id=805146 https://bugzilla.mozilla.org/show_bug.cgi?id=782215 https://bugzilla.mozilla.org/show_bug.cgi?id=798868 ------------------ Here is my TB configuration (from the "Help" -> "Information..." menu, German version): Allgemeine Informationen Name: Thunderbird Version: 16.0.2 User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:16.0) Gecko/20121026 Thunderbird/16.0.2 Profilordner: Ordner anzeigen (Lokaler Datenträger) Build-ID der Anwendung: 20121026120400 Aktivierte Plugins: about:plugins Build-Konfiguration: about:buildconfig Absturzberichte: about:crashes Speicherverwendung: about:memory E-Mail- und Newsgruppen-Konten account1: INCOMING: account1, , (imap) imap.gmx.net:993, SSL, passwordCleartext OUTGOING: mail.gmx.net:465, SSL, passwordCleartext, true OUTGOING: mail.gmx.net:465, SSL, passwordCleartext, false OUTGOING: mail.gmx.net:465, SSL, passwordCleartext, false OUTGOING: mail.gmx.net:465, SSL, passwordCleartext, false OUTGOING: mail.gmx.net:465, SSL, passwordCleartext, false OUTGOING: mail.gmx.net:465, SSL, passwordCleartext, false account2: INCOMING: account2, , (none) Local Folders, plain, passwordCleartext account3: INCOMING: account3, , (rss) Feeds, plain, passwordCleartext Erweiterungen Highlighter, 0.6.5, true, andre.rodier-highlighter@gmailcom Russian spellchecking dictionary, 0.4.4.1, true, ru@dictionaries.addons.mozilla.org United States English Spellchecker, 6.0, true, en-US@dictionaries.addons.mozilla.org Wörterbuch Deutsch (de-DE), Hunspell-unterstützt, 20120628, true, de_DE@dicts.j3e.de Wichtige modifizierte Einstellungen Name: Wert accessibility.typeaheadfind.flashBar: 0 browser.cache.disk.capacity: 1048576 browser.cache.disk.smart_size.first_run: false browser.cache.disk.smart_size_cached_value: 737280 browser.zoom.full: true extensions.lastAppVersion: 16.0.2 gfx.blacklist.suggested-driver-version: 6.14.10.5260 mail.openMessageBehavior.version: 1 mailnews.database.global.datastore.id: 19d79eb7-7865-4d82-a29e-3cbf82d5838 network.cookie.cookieBehavior: 2 network.cookie.prefsMigrated: true places.database.lastMaintenance: 1353266760 places.history.expiration.transient_current_max_pages: 26585 places.history.expiration.transient_optimal_database_size: 42534666 print.print_printer: PDFCreator print.printer_PDFCreator.print_bgcolor: false print.printer_PDFCreator.print_bgimages: false print.printer_PDFCreator.print_command: print.printer_PDFCreator.print_downloadfonts: false print.printer_PDFCreator.print_edge_bottom: 0 print.printer_PDFCreator.print_edge_left: 0 print.printer_PDFCreator.print_edge_right: 0 print.printer_PDFCreator.print_edge_top: 0 print.printer_PDFCreator.print_evenpages: true print.printer_PDFCreator.print_footercenter: print.printer_PDFCreator.print_footerleft: &PT print.printer_PDFCreator.print_footerright: &D print.printer_PDFCreator.print_headercenter: print.printer_PDFCreator.print_headerleft: &T print.printer_PDFCreator.print_headerright: &U print.printer_PDFCreator.print_in_color: true print.printer_PDFCreator.print_margin_bottom: 0.393750011920929 print.printer_PDFCreator.print_margin_left: 0.5 print.printer_PDFCreator.print_margin_right: 0.5 print.printer_PDFCreator.print_margin_top: 0.393750011920929 print.printer_PDFCreator.print_oddpages: true print.printer_PDFCreator.print_orientation: 0 print.printer_PDFCreator.print_page_delay: 50 print.printer_PDFCreator.print_pagedelay: 500 print.printer_PDFCreator.print_paper_data: 9 print.printer_PDFCreator.print_paper_height: 11,00 print.printer_PDFCreator.print_paper_size_type: 0 print.printer_PDFCreator.print_paper_size_unit: 1 print.printer_PDFCreator.print_paper_width: 8,50 print.printer_PDFCreator.print_reversed: false print.printer_PDFCreator.print_scaling: 1,00 print.printer_PDFCreator.print_shrink_to_fit: true print.printer_PDFCreator.print_to_file: false print.printer_PDFCreator.print_unwriteable_margin_bottom: 0 print.printer_PDFCreator.print_unwriteable_margin_left: 0 print.printer_PDFCreator.print_unwriteable_margin_right: 0 print.printer_PDFCreator.print_unwriteable_margin_top: 0 security.OCSP.require: true security.ssl.renego_unrestricted_hosts: mail.gmx.net security.ssl.require_safe_negotiation: true Grafik Karten-Beschreibung: Intel(R) Graphics Media Accelerator 3150 Vendor-ID: 8086 Geräte-ID: a011 Karten-RAM: Unknown Karten-Treiber: igxprd32 Treiber-Version: 6.14.10.5134 Treiber-Datum: 9-24-2009 WebGL-Renderer: Wurde auf Grund Ihrer Grafiktreiberversion blockiert. Versuchen Sie, Ihren Grafiktreiber auf mindestens Version 6.14.10.5260 zu aktualisieren. GPU-beschleunigte Fenster: 0/4. Wurde auf Grund Ihrer Grafiktreiberversion blockiert. Versuchen Sie, Ihren Grafiktreiber auf mindestens Version 6.14.10.5260 zu aktualisieren.

I too have this problem. I have Global Composing Preferences > General > HTML set to Bookman Old Style small. Various actions including pasting an image into an email body anywhere and hitting return cause the font to revert to variable width medium. This is very frustrating and I've put up with it for years through many Thunderbird upgrades and on a succession of computers. I've even developed work-arounds like hitting return a couple of times before pasting. It's my only complaint, and really, a relatively minor one, about my favourite mail tool.

I can confirm the same thing on Thunderbird 31.1.1. I just switched my parents to Thunderbird and set their default compose font size to "Large", and it keeps setting itself back to "Medium" when they edit and return to the end of the line. It's frankly embarrassing, especially as this bug has been reported so many times starting so long ago.

Screenshot of font problem.