Firefox doesn't start in Ubuntu 10.04

[Malfet]

After upgrade to Ubuntu 10.04 I realized that Firefox doesn't start, it just shows "Firefox starting"on the taskbar for a second and then dissapear. New Gwibber software doesn't start either.
I have separate /home partion and installed new version to the system partition marked it to be formatted first. Opera browser works perfectly fine.

Does anyone have any idea what can be wrong?

[Malfet]

Firefox problem solved - I've just reinstalled it in Synaptic, but Gwibber doesn't start anyway...