User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.3a1pre) Gecko/20100126 BetterPrivacy-1.47 Minefield/3.7a1pre Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.3a1pre) Gecko/20100126 BetterPrivacy-1.47 Minefield/3.7a1pre ID:20100126052630 During playback of flash videos from sites with certain flash video players, video stops updating (static image of last displayed frame) and audio-only continues. The whole browser interface, meanwhile, is hung and completely unresponsive. Killing mozilla-runtime.exe restores responsiveness to the browser. It doesn't happen with all videos and, for the hanging videos, it doesn't happen with IPC disabled. Videos, where I've experienced this hanging, including: http://www.cbsnews.com/video/watch/?id=6135088n http://www.cbc.ca/video/#/Shows/The_Passionate_Eye/ID=1396085855 Also, notice in the WinDBG log, I am attaching, as soon as video starts playing, there's a whole bunch of "(b3c.80c): Guard page violation - code 80000001 (first chance)" messages spewed, up until the hang. Reproducible: Always Steps to Reproduce: 1. Enable IPC plugins 2. Start one of the listed videos and allow it to play till video frames are no longer updating, but audio continues to play and the browser interface is hung 3. Once the browser hangs, notice that killing the mozilla-runtime.exe process unhangs the browser.

Based on the stacks there, the parent process is crashing in NPObjWrapper_NewResolve, and this is a dup of bug 542263.

I'm not sure this bug should be duped to bug 542263. With bug 540604 finally fixed, I was able to test bug 542263 and it crashes, instead of hanging, Firefox. For my issue, the crash in my WinDBG log is possibly only a symptom of running Firefox + IPC plugins in WindDBG. So, until bug 542263 gets fixed, I can't know for sure if the issues are really related. If there's a better way to get debug information for what I'm experiencing (i.e. not WinDBG), I'd appreciate it Tested with: http://hg.mozilla.org/mozilla-central/rev/035ca5e3ea54