Are you saying that front-to-back registration is off? That wouldn't be surprising on most printers.
I'm not sure what you mean by registration is off? Can you explain please? Is it my printer not my Indesign file that needs to be corrected?
Peter is asking if when you print it off that the pages aren't aligning up on both sides the way you want, i.e., when you trim and fold the pages they are offset on one side.
To counter this - you can measure on the sheet of paper exactly how much it is off and then on the pages that are off - you can shift these by the amount in InDesign.
Bit of trial and error but you'll get there.
While Eugen is coorect about what I'm asking, his solution may not work on every printer. Even relatively expensive commercial printers like the Minolta BizHub series and similar products from other vendors don't have the same sort of sheet-to-sheet tolerance for alignment that yo will find with a printing press because they use differnt technology for moving the paper through the machine.
It's not unusual to see drift through a long run of up to 3mm or .125 inch overall acros both the length and the width of the page when working with digital printing equipment. In general that's within the machine tolerance specifications (+/- 1.5 mm) for page-to-page registration, and the only thing you can do is design to account for the possibility and use margins large enough to hide a discrepancy.