Unable to open Corel Designer (12) images made from another computer.

Hi All:

I am a longtime user of Corel Designer. I have it installed on both my home and office computers. I have no problem opening files made on either computer, on my home laptop. However, when I make a vector image (saved as a DES file) on my home computer, it will not open (or import) on my office computer. 

Both computers were loaded with the same installation disk, Both applications work fine otherwise. 

Any ideas?

Thanks

Ben

PS: I have checked the "properties" on the files that do open at the office against the properties on the files that don't open...no difference.