Oh god, it's one of those ones? I have a PS2 s-video I keep lying around specifically for Ico, and, I guess, this too now. From what I understand, it's not about the cable, but rather your TV's ability to display a 240p signal; some do, some don't.
For what it's worth, the DS version is enhanced, and is cheap now as well (currently $13.05 on Amazon). So if you've got a DS, you're really better off just going with that.
And yeah, I was simplifying, but it's the 240p signal that's the issue. Apparently it never occurred to early PS2 developers that coding to output a non-standard signal would be an issue. I actually didn't know that Ico was one of those games as well -- glad to know that before dropping the cash on it. Now I hope even more that they put out a PS3 "remastered" version.
Edited by arcane93, 16 March 2010 - 03:14 AM.