Printer will not obey InDesign print presets

I edit a small weekly newspaper. We used to print a proof-reading copy of each page, direct from InDesign (CS4) on 11 x 17 paper at 74%. We swithed from a Cannon 5035 to a Cannon iR-Adv C3725 printer. At first we didn't have any issues after the switch.

Now, however, it will not obey our presets. We have a couple of diffeeent preset options, all of which on "setup" have "defined by driver" on paper size, 11 x 17 , with portrait orientation, then, under "options," width & height both set at 74%, with Constrained Proportions checked & "centered" as the page position.

In the last 2-3 weeks, the printer insists on printing it on 8.5 x 11 papeer, scaled to fit it (which is maybe 40% scale & almost impossible to proof, even with a good magnifying glass). 

Any ideas what wecan do to make tye printer comform to our preset specs?

Mark