[TYPO3-english] Typo3 4.2.9 - Clear cache menu not responding

[MT]

Hi

I have a fresh install of Typo3 ver. 4.2.9.
The "Clear cache" menu to the top right (orange lightning) is not working, 
the cache menu is not showing.

I can remenber having had the same problem before but can not remember what 
to do.

Any help?

Kind regard
-Marianne