Monitor or Graphics card at fault?

Help! Damsel in distress :(
I have been having problems with the monitor and grahpics drivers. The monitor cuts out and stops responding at certain times and sometimes when you boot up the computer the monitor does not come on it just flashes like it is on standyby mode. I have downloaded the lastest drivers from ATI and windows update and this seemed to fix the problem, but now it has started to happen again. The graphics card up to this point has worked fine (Connect 9800 Pro). Could it be the new monitor? (Samsung SM793S 17ins Fst 0.23 96khz TCO03)

Could you please help me with this?