G4 "cannot sleep case open"...but closed!

says it cannot sleep because the case is open...but its not!
tom wrote on :
Hi! I recently pulled 2 scsi cards out of my mac that had been in there for probably two years. I was really looking forward to being able to use yhe sleep feature once again, the way I had before installing these pci scsi cards. Only now, it(G4) says it cannot sleep because the case is open...but its not! I have checked a dozen times looking over the hinged/connection area to make sure nothing looks awry. Do any of you have any ideas? Thanx, Tom