I am revisiting this issue. I had solved it by printing via the Fiery Command Workstation which has all sorts of options not available through the printer key panel.
I am printign double sided business cards which must be EXACT! If I print via the Internet Services interface, there are no options for quality, etc. And the print is reduced in size. We are not printing edge to edge.
If I use the flash drive and USB port, the rinter stiull resizes the file. There is absolutely no way I can figure out how to stop the xerox (we have two, and both do it) from shrinking (it will enlarge if printing to 11x17)
With most print jobs such as fliers, nobody is measuring or cares if it is 1/16th of an inch off. The business cards have to be exact, no fudge factor here.