locking up solidworks changing material to sheet metal part

I have a sheet metal part complete. When I go back and try tochange the material and add a gauge table Solidworks 2008 SP 5.0LOCKS UP! I have tried several different parts and the outcome isthe same on all. Will I have to start the parts over from scratch?

Thanks,

Kurt Mette
Product Designer
Solidworks 2008 SP 5.0SolidworksSheet Metal