I thought PBP had GLCD support?? I say that because I've been using one with it for over two years now and there are plenty of examples of it on this forum. Maybe I've got the wrong end of the stick with this problem, but have a look around.

BTW I suspect you have one of the control lines shorted somewhere in your simulation diagram. Proteus is like Protel for putting wire link dots in random places where wires cross, a pain in the a** most of the times.