User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:21.0) Gecko/20100101 Firefox/21.0 Build ID: 20130430204233 Steps to reproduce: Start Firefox. I'm on a 2012 MBA with SSD and 8GB RAM, and startup did not take any longer than ~1 sec. I'm not exactly sure about the actual STR. Might have been during restart just after prompting to update from b5 to b6. Might have been because network was disabled (I don't remember that exactly). Actual results: Slow startup warning was displayed. browser.slowStartup.averageTime = 18441 .samples = 1 .timeThreshold = 60000 Expected results: No warning message. The ~20s startup time (in the config) hints to this happening because timing startet before the update was applied, and ended after full startup after the update. If this is the case, a notice should not be displayed immediately after update. FHR data.last (excerpt) = "org.mozilla.appInfo.appinfo": { "_v": 2, "appBuildID": "20130430204233", "distributionID": "", "distributionVersion": "", "hotfixVersion": "", "id": (upon request), "locale": "de", "name": "Firefox", "os": "Darwin", "platformBuildID": "20130430204233", "platformVersion": "21.0", "updateChannel": "beta", "vendor": "Mozilla", "version": "21.0", "xpcomabi": "x86_64-gcc3" }, "org.mozilla.profile.age": { "_v": 1, "profileCreation": 15816 }, "org.mozilla.appSessions.current": { "_v": 3, "startDay": 15828, "activeTicks": 81, "totalTime": 469, "main": 792, "firstPaint": 17929, "sessionRestored": 18379 }, "org.mozilla.sysinfo.sysinfo": { "_v": 1, "cpuCount": 4, "memoryMB": 8192, "architecture": "x86-64", "name": "Darwin", "version": "12.3.0" }

Probably solved by Bug 838713, then this may need an uplift.

Oh, landed already in Fx 21. Then it may not work as intended (if my original assumption is correct). (Sorry for Bugspam.)

I'm still occasionally getting bogus slow-start warnings on Nightly. Bug 868712 might be part of it, but is probably not the only thing going wrong.

(In reply to Jesse Ruderman from comment #3) > I'm still occasionally getting bogus slow-start warnings on Nightly. Bug > 868712 might be part of it, but is probably not the only thing going wrong. You've been seeing this behavior since FF22 on Nightly as well? Or was it even earlier? There isn't enough info to go off of to block the release of FF22 on this change, so wontfixing.

This looks like an intermittent issue and something we may not be able to block unless we have reliable STR or more reports. Please fell free to renominate if there is a disagreement here.

I filed bug 896025 for the same problem, I have some useful info there, I'm investigating whether I can find anything more since I still have the session ongoing.

I haven't been able to reproduce this on recent builds. Does anyone still see this issue?