User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6 Build Identifier: version 2.0.0.6 (20070728) I was dragging a couple of messages from my inbox to another folder. While I was dragging, new mail arrived in third folder (not my inbox or the target folder). The message subject pane (showing my inbox) updated and no longer displayed the messages as selected (it switched to just showing the last message I added to the multiple selection). The drag-n-drop cursor was still showing, and dropping on the target folder still moved the originally selected messages appropriately. Really, the main problem is that visually it looked like the drag-n-drop operation forgot my message selection. This is quite disconcerting, especially if I've just made a complex multiple selection. This problem does not occur if the new mail arrives in my inbox (maybe that's just because my inbox is what's open in the subject pane). Reproducible: Always Steps to Reproduce: 1. Select several messages in a folder. 2. Start dragging them to another folder. 3. Don't drop them in the other folder, but instead wait for new mail to arrive in a third folder. Actual Results: Multiple selection in the subject pane is no longer displayed. Subject pane switches to only having one message selected. Expected Results: Subject pane should still show multiple selection. Using IMAP with Thunderbird filtering the incoming messages. mail.check_all_imap_folders_for_new is TRUE. Also using the Classic view with the Message Pane on.

wow, don't know how I missed this bug Marc, does bug 458570 sound similar? are you able to test trunk builds as we attempt to figure out this bug? ftp://ftp.mozilla.org/pub/thunderbird/nightly/latest-comm-1.9.1/

Bug 458570 does sound similar, except that my experience was much more benign. However, IIRC I did not have any active new-mail alerts (no popup or sound). I can run nightlies, but since reporting this bug I've moved to a completely Linux environment with server-side filtering of incoming messages, so I may not be able to reproduce the issue. I'll give it a shot.

In my current configuration with today's nightly -- Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.1.1pre) Gecko/20090703 Shredder/3.0b3pre -- I did *not* see this issue. But (aside from the Thunderbird version) the main things that are different for me now are: - Linux instead of Windows. - Server-side filtering instead of Thunderbird filtering. - Thunderbird's junk mail controls are now OFF (they were on before, something I didn't mention in my original report).

Marc isn't using the same environment, so isn't seeing this issue. Rather than close WFM or incomplete, I am duping to the closest match. There is at least one other possibility however - I believe a compact in the background can also cause selection to be lost. But I don't Marc's issue was compact related.