I'm creating ad graphics in CorelDRAW12 at 3.75"x3.75" and saving them. When I reaload them in CorelDRAW they are still at that size, but when I export them to PDF (prepress) and print them out, they are coming out at exactly 3.5". This is screwy. I suppose I could figure out the percentage I need to save them as to get them to come out the right size, but that's a chewing gum and duct tape solution. I must be doing something wrong. What is it?

Any thoughts appreciated.