The PS3 backwards compatibility is reputedly a little crumbly around the edges. Says aged-gamer bastion, 2old2play:
I’ve seen a couple blogs coming up with lists of bugged or nonfunctional games, such as this post on Siliconera. 196 is a rather high number, however. With the locked-out games being worked on in the same henpecking method as the Xbox team uses, what’s the turnover rate going to be?
One more reason that missing out on a launch PS3 might not be such a bad thing. I’m fine with waiting.
PS3 Back Compatibility: Not Perfect [2old2play]