Aren't you supposed to use WMP10 with TIVO? Is it supposed to work with 9?

When I installed the Core Media Player, I set it as the default media viewer, so when I click on a program in the TIVO desktop library it brings it up in Core instead of WMP. Might that make a difference? Again, haven't played with it too much, but it's driving me crazy trying to work around the commercials by hand, so the 30 second jump feature in Core might be what I'm looking for.