• One of addon may causing the issue, try to disable one by one from Addon Manager (CTRL+Shift+A) and check which one is causing the issue.
• you can reset your Firefox too, it will keep your bookmark intact, but will delete your addon and other junk toolbar
• http://support.mozilla.org/en-US/kb/reset-firefox-easily-fix-most-problems

let us know if its helps

According to the System Details List are all extensions disabled.

Try to disable hardware acceleration in Firefox.

• Tools > Options > Advanced > General > Browsing: "Use hardware acceleration when available"
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

In Firefox Safe mode these changes are effective:

• all extensions are disabled
• the default theme is used (no persona)
• userChrome.css and userContent.css are ignored
• the default toolbar layout is used (localstore-safe.rdf)
• the Javascript JIT compiler is disabled
• hardware acceleration is disabled

• plugins are not affected
• preferences are not affected

D: i delete all of my profiles, and the option "Use hardware acceleration when available" is the solution.

Thanks!!!