- Twitter doesn't show a pop-up reply 'window' when clicking on Reply. Pop-ups aren't disabled, happens even with no add-ons enabled. - Hotmail search doesn't search when pressing either enter or the search button. Again, all addons disabled. - Foxyproxy doesn't affect 4chan proxies, only after restarting. All addons exept Foxyproxy disabled. Google and other services are not affected. Everything works normally on another Firefox profile (same computer, same Firefox.exe). Profile has same issues when copying to another computer. (Clean install, clean everything) I however do not want to lose any bookmarks or website preferences (through addons). Is there any way to fix it, or will I need to create another profile, re-do everything manually again and remove the old one? Also, I use nightly, but the problems existed long before I upgraded to Nightly, and the upgrade did not solve any problems. On a less related note: YouTube (or generally all Flash movies) are choppy: They play jerky every 10 seconds, but smoothly in between the jerks/hiccups. It doesn't appear with either IE9 or Chrom*, so it's either Flash-plugin related or Firefox related. Any idea how to fix this? I'm getting tired of firing up another browser just to watch YouTube.