Flash Player Debug version causes Firefox to crash
Somewhere around version 3.6.x Firefox changed something which caused Flash Player Debug version to crash my Firefox all the time. This problem was causing me nightmares because A LOT of sites I surf have Flash with all sorts of unhandled errors (which debug player pops up for me to debug). Instead of just poping up debug window and waiting me to dismiss it, Firefox was "thinking" about the problem 45secs to indefinetly. Only solution for me was to end "plugin-container" task from processlist.
Solution is to go in to the Firefox config settings (type about:config in to the location bar) and search for dom.ipc.plugins.enabled.npswf32.dll. Double click that to set it to false.
You may also need to set dom.ipc.plugins.timeoutSecs to -1.
Restart your browser afterwards and that's it.