[TYPO3] How to connect to TYPO3 when client is behind a proxy?

[Andreas Balzer]

Olivier Dobberkau schrieb:
  > OK. Any Chance that you can have a look at proxy logs?
> Or cant you just log in to the backend?

Hi!
I can't have a look into their proxy log or any proxy files. (I don't 
even know what proxy they use) but I have full access to the TYPO3 
backend and I recognized that the FE somehow works if I pass nocache=1 
all the time. The strange thing is, that typo3.org itself works 
completly fine. But for example www.ess-erfurt.de doesn't.

Andreas