Using Native Inspector Very Frequently Breaks CSS on Various Pages Completely Arbitrarily.

Question

Hello, I'm running Firefox 19 on Mac OSX 10.8.2 and I do web development sometimes.
Lately, I became a big fan of the native inspector inside Firefox and I began using it often. At least 100 times a day.
I found that using it this often breaks CSS on random pages, often pages I've never visited before. Around one in every 1000 pages is broken and the same sites are broken over and over.
For example, my hosting's cPanel refuses to fetch the background images for the icons. There are pages where CSS stylesheets don't load at all (even though I can access them via view->source) and sometimes, the inspector itself just breaks and travels with me from tab to tab, site to site (I can't close it, have to close and re-open the window).
I know I could create a new Firefox profile and manually copy over select content like my bookmarks, browsing history, etc. But before I resort to that is there some kind of a proprietary cache that is kept by the inspector that I could reset?
(I've cleared my regular cache and cookies with no results).
Thank you!

Answer 1

Did you check if installed extensions aren't causing this problem?
Start Firefox in <u>[[Safe Mode|Safe Mode]]</u> to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).
*Do NOT click the Reset button on the Safe mode start window or otherwise make changes.
*https://support.mozilla.org/kb/Safe+Mode
*https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes