sinclair_tm

If you can open the pics on the Mac, you will be fine for backing them up. I'd burn another disk just to be certain.
As for your Mac, I would reset the PRAM, do that by holding down the command-option-p-r keys all at once when you turn it on, keep holding them until you hear the startup bong at least 4 times. If that doesn't work, I'd reset the PMU, but I'd have to know exactly which Mac you have to do that as they all do it differently.