ubuntu crash when close firefox in jaunty

Precise more , what have you installed lately , and what configuration you have modified in firefox.

before i upgrade from 8.10 to 9.04 there is no problem with the firefox, but when i have finished upgraded,and i try open firefox, the problem always appear, and i have do it 3 times.

notes : sorry my english is to bad....:-(

Can you go into your home directory Places > Home Folder and type CTRL + H

Now look for the following directory:

.mozilla

Delete it (right click, Move to Trash) or on your keyboard just tap "Delete."

PLEASE NOTE: This will delete your extensions and current Firefox history & preferences.

Now go to SYSTEM > ADMINISTRATION > SYNAPTIC PACKAGE MANAGER

Enter your user password.

Search for "Firefox"

Once found right click on the Mozilla Firefox package(s) and go to "Reinstall." Now click "Apply" in the upper left hand corner.

Restart your system. This is not necessarily required, but often resolves a lot of the issues you are stating.

Let me know if this worked.

Also, remember to empty that Trash Bin ;)

You don't need to reinstall firefox , try before to do this:

01- goto /home/USERNAME/.mozilla/firefox
02- delete all files and folders
03- Reopen firefox.

Good luck.