One of the older version of WMP could open Real Player files I
think. If I'm not wrong, it's version 8. I've got one song in .rm
format, surprisingly it played. Usually, it would skip or give
errors in newer players.
As the name implies, it's still in Beta, don't expect a lot of
goodies yet. In fact, problems with ripping DVD might just be bugs.
Otherwise, it could be like ditzy says, some protection codes in
the program. 
