Stuck in Grey Screen

Ok, so I have my Macbook partitioned with Vista Ultimate and Mac os X tiger. I was messing with vista, and closed the computer (puting it to sleep and such). I come back few hours later, and try logging in. It freezes at the log in screen. I hold the power button to shut it down, and then try booting it back up. It is stuck in grey screen, and beeps once at me periodically. I am not sure what to do about it, or even what the problem is. Everythign was working FINE just a few hours earlier. now i can't even get into any type of command prompt, it just won't go anywhere. I've tried resetting pmu's, and taking otu the battery and such, no luck. Ideas, anybody?

how old is the macbook

An amazing 4 months.

what were you messing with

try booting off the cd and try selecting on of the startup disks

I was messing with it by trying to log back into Vista, lol.
I tried that, now all I am getting is a folder w/ a big ?. Hard drive failure isn't represented by that...right? right?

hope this helps:
http://kb.wisc.edu/helpdesk/page.php?id=913