|When in safe mode only the minimum drivers are loaded.|
Sound like one is missing or corrupt.
This is based on the computer booting when out of safe mode and all the drivers are loaded.
You can try a repair with your install cd.
Get drivers from dell using your service tag
Or if you are really into working on computers download one of the driver packs that are online.
I use one from http://03compu.ru/ It is in russian but there are english versions out here. It's like one of the many driver programs you see on the net ...except its all on 1 cd and is free....and does not require installation.
My best guess is your missing a driver.