Comment 13 for bug 363533

I've hit this too - Dell XPS Studio 16, Radeon HD 3670. Here's what I've found:

Without fglrx installed - Suspend, hibernate and Resume work fine
With fglrx installed - Suspend, hibernate and Resume work fine
With fglrx installed and compiz active - No resume from suspend or hibernate
With fglrx installed, compiz not active, but playing Tux Racer - No resume from suspend or hibernate

It seems that when fglrx is actively displaying 3d images, it'll prevent a successful resume. I've tried Tux racer at the menu and actually playing, with the same results.

It seems then that this problem is NOT related to compiz.