iPod Touch 4G, "Video" program crashes after Update to iOS 4.2

After updating iPod Touch 4G to iOS4.2 the program "videos" just crashes.
Details: I can sync the iPod touch with the computer and the videos reappear on first launch of "videos". All videos play o.k. Second launch of "videos" gives me a white screen for several seconds, then "videos" crashes. Every time I launch it, it keeps crashing.
There are 2 conditions that make them reappear and "videos" runs normally (but only once!):
Method 1: Sync with my MacBook
Method 2: I fully close the program "Videos", then change language on the iPod touch to english (any other language seems to work, too. It's the change that seems to be important). Launching "videos" after that successfully shows all my videos. Second launch and the crash is back. Every time. Until I change the language again.
I tried full restore, and I tried Resetting the iPod, both with no success.
BTW: The Video Files are o.k., I can launch them using playlists and they work just fine.

This is really strange. Can anyone help?

Or, can anyone help how to revert back to iOS 4.1?