Edit: Nevermind, reread your post and it has to be
CF with that much wattage (well, that or
HO/
VHO)...so going the hardware store and picking up a $15 ballast doesn't really apply.
Yeah, I'd call up the manufacturer to try to get a replacement...it's almost certainly the ballast. Otherwise you're looking at picking up something like an Ice Cap ballast on eBay for as cheap as possible, or ordering one online. They're the most expensive part of a lighting setup, unfortunately.