User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:2.0b4pre) Gecko/20100817 Minefield/4.0b4pre Build Identifier: Mozilla/5.0 (Windows NT 6.1; rv:2.0b4pre) Gecko/20100817 Minefield/4.0b4pre It has occurred 2 times for me. The first time is upgrade of Firegesture from 1.6b4 to 1.6b5, on a 4.0b3pre nightly build. The second time is on the nightly build of 4.0b4pre 20100817, after upgrade Webmail Notifier from 2.5.5 to 2.5.6. The symptom is the just upgraded addon(by addon manager) disappeared after restart. Reproducible: Sometimes Steps to Reproduce: 1. Open addon manager. 2. Click the "update addon now" menu drop. 3. Firefox find a updated version of an addon, and installs it automatically. 4. Restart the browser according to it's prompt. 5. After Firefox starts, open the addon manager, the just upgraded addon is no longer there. Actual Results: The addon disappered as if it was uninstalled instead of upgraded. Expected Results: The addon should be there with the upgraded version. I can not reproduce it every time, but it did happened for me for two times. Both times are happened when addon manager automatically download upgrade for me. I have upgraded addons manually for several times(>10) but not yet meet similar problem.

Please attach extensions.log from your profile folder. http://support.mozilla.com/en-US/kb/Profiles

dupe, canceling blocking request.