User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ja; rv:1.9.2.2) Gecko/20100316 Firefox/3.6.2 (.NET CLR 3.5.30729) Build Identifier: 3.0.3 viewing tab closes when a new message download. This matter do not happen when viewing a message in main pane. Reproducible: Sometimes Steps to Reproduce: 1.Open a message in a tab. 2.Download some new message. (keep viewing the tab) Actual Results: Close the tab and focus moving to a new massege. Expected Results: Do not close the tab.

Have you tried safe mode? (see https://support.mozillamessaging.com/en-US/kb/Safe+Mode for more information) Also, this looks somewhat like bug 517443 -- try disabling Tools -> Options -> Advanced -> Network and Disk Space -> Compact folders when it will save over ___ KB, and see if the problem continues.

faithfully0914 could answer to comment #1?

(In reply to comment #1) > Have you tried safe mode? (see > https://support.mozillamessaging.com/en-US/kb/Safe+Mode for more information) > > Also, this looks somewhat like bug 517443 -- try disabling Tools -> Options -> > Advanced -> Network and Disk Space -> Compact folders when it will save over > ___ KB, and see if the problem continues. I tried safe mode, and a optional setting. But few this bug is there. (frequency is lower)

Is there any error message like bug 520115 comment #0, bug 520115 comment #1, or bug 520115 comment #7 in Error Console?

faithfully0914, so you do see this if you disable auto compact? do you still see this in v3.1?

(In reply to comment #4) This message in Error Console. -- エラー: this.search is null ソースファイル: file:///C:/Program%20Files/Mozilla%20Thunderbird/modules/dbViewWrapper.js 行: 756 -- (In reply to comment #5) "auto compact" is "compact folders"? It was disabled. But it bug is remains. I'm using version 3.1.7.

(In reply to comment #6) > "auto compact" is "compact folders"? Yes. Tools/Advanced/Network and Disk Space, [?] Compact folders when it will save ... If this opsion is enabled, set mail.purge.ask=true via Config Editor(Tools/Options/Advanced/General). Dialog is shown before start of auto-compact, and you can cancel auto-compact.. > Error: this.search is null > Source File: file:///C:/Program%20Files/Mozilla%20Thunderbird/modules/dbViewWrapper.js > Line: 756 This error is shown in Bug 545218.

let's mark it depends and see what happens.