The Reset Firefox feature can fix many issues by restoring Firefox to its factory default state while saving your essential information. Note: This will cause you to lose any Extensions, Open websites, and some Preferences.

To Reset Firefox do the following:

1. Go to Firefox > Help > Troubleshooting Information.
2. Click the "Reset Firefox" button.
3. Firefox will close and reset. After Firefox is done, it will show a window with the information that is imported. Click Finish.
4. Firefox will open with all factory defaults applied.

Further information can be found in the Reset Firefox – easily fix most problems article.

Did this fix your problems? Please report back to us!

Start Firefox in Safe Mode 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

You can also check for problems with the localstore.rdf file.

• http://kb.mozillazine.org/Corrupt_localstore.rdf

Question owner

Hi yes

I have started in safe mode. 
I have formatted and reloaded the entire operating system  
I have reset Firefox 
But still have the  problem
I have Three  partitions with two different versions of Ubuntu 11.10 ...12.04   they all    have the same symptom,  But windows7 doesn't

Modified February 1, 2013 7:30:21 AM PST by Mike-me

Chosen Solution

Hi.

I also want to join this conversation, because I also see this translucent rectangle then firefox starts. I have Firefox 16.0 on virtual machine and it doesn't exhibit this behaviour. I am sure this is not a bug, but it looks ugly. Firefox is very good browser and should show its main window immediately.

Thanks

Firefox 19 (Linux x86_64) solved this issue.

Thanks.