[TYPO3-english] Funny behaviour win Typo3 4.3.1

[Jens W. Skov]

Hi 

I've just upgraded and old Ubuntu 6.60 to 8.04 and after that upgraded Typo3 from 4.2 to 4.3.
I have no front end problems at all. But the backed is really funny :-)
In IE8 it keeps telling that the sessions is expiring in 30 sec as soon as I log in.
In Chrome I have it all working but I have to wait very long time for the site tree to appear. 
I firefox I can't click anything.
 
Any idea what I might have missed?

mvh. 
Jens W. Skov