Yes, the infamous Mac compaitability monster rears its ugly head.
The main reason why different sets of hardware have issues isn't the proprietary soft/hardware on Apple of Serato's part, but because of the new Intel Dual Core chips. A buddy of mine had troubles as well, but I guess companies are releasing updates and patches to remedy these basic problems. Hell, up until a few months ago, OSX Tiger was't compaitable with FS2, which was a HUGE problem, considering they came out with only a year in between their release times. And we all know, that a year isn't really long especially if you've invested that much money in a laptop, the Tiger upgrade, and FS2/SSL.
Even FS2 wasn't compaitable on Dual Core based machines when they came out!
But rest assured, things are better now, and will continue to improve, as the DC chips are fairly new, and I don't see them going out of tech-style anytime soon,
Hope that helps!

BTW, DJ Woody, doesn't PvD use a 15" Powerbook for his gigs?