The only thing I can think of is that your laser might be trying to go out of whack.
Good God don't say that! The PS2 I have now is about 2 weeks old (New from Gamestop) so I don't think (hope) that is the problem.
Rise of the Kasai is the only game giving me problems like this. (It comes on a regular silver bottom DVD - all the other ones play fine.)
The disc is in perfect condition, as was the last one I got.
Any other ideas?