Front Row does not load trailers any more

Unfortunatelly the original thread is blocked, so no more answers can be written in it ( http://discussions.info.apple.com/thread.jspa?threadID=2307347&tstart=165), so I start a new thread. Because I found out what at least part of the problem is.

We have 4 Mac's in our household, 3 of them play the trailer without problems, only the Mac mini connected to the TV does not load and play them any more, not even the trailers list (just the one where it would be needed).
The OS is up to date on all computers, Quicktime 7 is installed on some of them, so there is no relation to that. But it seems to have a relation to Front Row Trailers PrefPane. It was installed only on the Mac mini which does not load the trailers any more.
By analyzing the network accesses with Little Snitch I found out that the not working Front Row does not connect to the following server/homepage:
trailers.apple.com
www.apple.com

The Mac's with working trailers connect to these two servers as soon as you select Trailers in Front Row.

So, I expect, if someone can tell me which file contains the server addresses for Front Row, I could solve the problem.
(It is not in the Front Row app, copying the complete app from a "working" Mac the "not working" does not make any difference.)

Regards
Philipp