[TYPO3-debian] Extension installation problems

[David Cake]

	I'm running typo3 4.02 on Debian sarge (with PHP5 and a few 
other changes).
	My problem is that I am having trouble installing new 
extensions. Either when list/look up reviewed extension, or when I 
attempt to upload a t3x file, I get the same result - the page never 
loads, and I end up with the main pain being plain white, and when I 
am uploading I can't see that it ever succeeds.
	Its not a permissions problem in the ext directories.
	I'm not sure how to debug this problem  - any suggestions?
	Regards
		David