[Chimera-users] volume viewer issue

Hi, I am using chimera to visualize a stack of EM serial sections. I can load them into Chimera (as MRC file), but when I try to view the stack in the volume viewer w the "solids" option all I see is a white square.. w the mesh and surface options the stack shows up as a grainy image on which it's difficult to see any depth.. any suggestions? THanks, Matt