Art Not Printing At Actual Size

I have a Lexmark E250DN printer. I am a graphic artist so I need the printer to print accurately, which means to size.

THE PROBLEM: I am designing a parking permit. The outside box is 3-5/8" x 8-1/2" with copy inside it. When I print the .pdf art file on this printer, it prints the file as 3-9/16 x 8-7/16, whether on the postscript (PS3) or XL driver. To an artist, this difference is critical. It means I cannot trust anything designed and printed on this printer anymore. All the sizes would be way off.

When I take the same file and print it on three other printers, (Lexmark Optra S 1250, & two HP printers) the outside box is 3-5/8" x 8-1/2" on all of them.

THE REQUEST: Can I somehow correct the inaccuracy of the E250DN printer? If so, how?

Ptaker