I've been having Firefox problems on both platforms this week, and I suspected that the SwitchProxy extension was at fault. (It's the only extension I have installed on both platforms.) I found this corroboration:
I digged a little deeper and found the culprit: it's the switchproxy extension! By default it "phones home" to see if new updates are available. The developer's website is offline though, so it makes the browser freeze. On slow PC's and/or slow connections it looks as if it hangs.The poster recommends turning off auto-updates for extensions in Firefox preferences. Unfortunately, that 'fix' hasn't worked for me. I continued to get hangs until I uninstalled SwitchProxy. (Which sucks, cause I use it all the time.)
Does anybody else feel like it's time for a centralized, trusted repository for extensions?