Mac/ATI Ripple Water Bug?

Okay, so this is trivial at best, but I am very envious!!!

My brother let me install SL on his PC with one of the best NVIDIA graphics cards. I logged in, put all the settings to the top to see what this baby could do.

And lo and behold ... THE WATER ACTUALLY SURGES!! I've often wondered how we could get the water to move more than the reflective ripplage we see without "ripple water" turned on (that really should be called "wave action" or something). I've never turned that on on my Mac, since it says it'll slow me down and I have an ATI card LOL.

Well, it doesn't work on my Mac, no matter what I do. Is this an AGP only thing ? I'm drooling over how awesome the water looks (as I often thought it should have waves in it, we're not in a lake after all!). Any other Mac users try this feature out ? I'd be interested to see if it's a bug in the ATI thing.