I posted here on wednesday about my pc (dell 2400) not finding or recognising my graphics card (Geforce 6200). Well suddenly it started to work and I've installed it fine. But, when I start to play a game it's like the graphics card shuts down, like is not being powered. I have to restart the pc with my monitor plugged into the on board graphics card, which is disabled. The pc starts up in a safe mode. Could it be the power unit? Or am I missing something completely different? The power unit has a max of 250w. Any ideas?