Officejet not printing

[depawl]

This is a new HP Officejet 5610. I purchased it from Staples a couple weeks ago and set it up and got it printing no problem. I didn't use it for a week or so, and yesterday tried to print something, and it just prints out a blank page. The computer recognizes the printer, and sends a print job ok, the printer prints it, it's just that the page is blank. I tried a test page both from Windows and from the HP maintenance utility. I tried removing and reinserting the print cartridges, aligning and cleaning the cartridges,etc. No matter what, it just prints out a blank page. This one's got me stumped.
Thanks.