On Windows, start using the 'Safe Mode' shortcut created in your Start menu or by running firefox.exe -safe-mode. If you encounter strange problems relating to parts of the browser no longer working, the browser not starting, windows with strange or distorted appearance, degraded performance, etc, you may be suffering from Extension or Theme trouble. Poorly designed or incompatible extensions can cause problems with your browser, including make it crash, slow down page display, etc.Zooming out on some sites may result in grey or black lines appearing (see bug 468496).Firefox may have difficulty playing system sounds in some distributions of Linux (see bug 536996).Some slower machines may see degraded mouse responsiveness when viewing certain Flash videos (see bug 561818).CNet has been notified of the issue (see bug 569104) Older Flash videos on may fail to play.Content over certain Flash videos may not disappear when the video plays (see bug 571313).If FIPS mode is enabled and certain files have been removed from the system, the browser may crash on startup (see bug 522041).

This list covers some of the known problems with Firefox 3.6, which will be resolved in future releases: All Systems

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