Why is there an extra blank page that comes out of my HP 4..

Why is there an extra blank page that comes out of my HP 4M with every page
printed. If I print a 4 page document, 4 blank pages come out, one blank
right after every page. This only happens when I ask to print from my Vista
machine, my printer is plugged into my network and is controlled by an XP
machine. When I print from my portable (XP) or my other computer (another XP)
everything is OK, but with my new Vista computer, blanks always come out.
Please respond, I am tires of putting the sheets back in.

Thanks