Graphics Card
Nil - Using either built in built in Radeon 7540HD or the Radeon 7000 series built into the mobo? When connected the Device Manager shows only 1 x Diplay Adaptor Radeon 7540HD. 

AMD Catalyst Driver Version, and Driver History
Tried the latest stable catalyst driver.

Operating System
Windows 7 64 Bit

Issue DetailsWhen selecting a resolution above 1024 x 768 the monitor screen goes black every 5-10 seconds, the higher the resolution the more frequently the display dissapears.

I have managed to plug in an old nVidia 6600 Gfx Card and have set the reolution to 1600 x 1200 and the screen is steady as a rock??

Motherboard or System Make & Model
ASRock FM2A75M-DGS

Power Supply
Corsair System Builder CX500 

Display Device(s) and Connection(s) Used
Samsung Syncmaster SB23550VS connected via a VGA cable to the onboard VGAa Port (Monitor does not have DVI) 

Applications and Games
N/A

CPU Details
AMD A6 5400K 3.8Ghz Unlocked Dual Core Processor (Running at standard frequency i.e. Not Overclocked)

Motherboard BIOS Version
N/K I have not updated since installing.

System Memory Type & Amount
Crucial Ballistix 2 x 4GB DDR3 1866 L9 1.5 UDIMM Finned.

Additional Hardware
1 x Samsung HD103SI SATA HDD

1 x Seagate StM32503 18AS SATA HDD

1 x Sony Optairc DL DVD RWD SATA

Additional Details
Plugged in a differenet monitor and experienced the same problem.

"Speed is just a questionof money - how fast do you wanna go?"