After installing Win7 RC on my production Media Center box (ie the box I literally can't watch TV without) I noticed an annoying problem.
The skip forward & back buttons didn't work!
At first I feared the issue was an intended "by design" change. After all, I'm sure the commercial TV networks don't like us skipping over their ads. Fortunately, it seems it's a compatibility issue between Win7 RC and my IR receiver (in case, Zalman HD160, IRTrans).
Map the IR codes to the keyboard equivalents for the skip buttons via the following changes in %ProgramFiles%\IRTrans\remotes\apps.cfg.