According to this bug report: https://bugzilla.mozilla.org/show_bug.cgi?id=1189266
1189266 – crashes in atidxx32.dll/atidxx64.dll (more prevalent in windows 10) there is an issue of compatibility between Firefox and AMD video drivers:
"FWIW, we confirmed that this is fixed in the upcoming driver release."
I've been experiencing constant Firefox freezes while other browsers work just fine.
I'm on Windows 10.
The latest driver release is dated 7/28/201: Desktop
Any word when any new driver fixing Firefox issue will be released?