Display or Graphics Card Not Waking Up After Sleep

Was just wondering if anyone can help. I just built my first computer and for some reason whenever the computer goes to sleep I can't bring it back on. The screen just stays black and switches between the digital and analogue inputs until it times itself out. No keys on the keyboard or mouse clicks will bring it back on. I had sleep mode turned off (High Performance Mode in the energy saver prefs on win 7 - display sleep on but hard drive sleep off) and it still did the same thing. Leads me to believe it might not actually be sleep mode but either my screen or gpu freaking out?

If someone can run me through some checks to rule out the problem that would be great.

System:
i5 3470
GTX 295
ASRock B75M
Samsung SyncMaster P2350
8GB Corsair Vengeance
80GB Maxtor DiamondMax 10
1TB Western Digital Green