Turn the chassis intrusion part of the BIOS off? It'll be a sensor somewhere that's misbehaving
the little black switch ok that detects when teh lids been removed ? oh and have you reset the warning in teh bios as im not sure it goes away by its self when you open teh box
Flash it, I had to do that last time one of our Poweredge's went tits up.
Unable to even access the BIOS. The fans in one of the power supplies runs but the power doesnt kick in properly im guessing due to the error.