Problems with printing mail merged business cards.

[Rodge2]

I have mail merged some business cards using Word. I entered the code number of my avery business card blanks, and I have checked the dimensions of the cards are correct. The problem is that when I print them the first two cards (side by side) are fine, but then they begin to get out of alignment and end up printed across the perforated bits. It is as if the whole document is too high up the page. I am convinced it is something set wrongly on my printer (HP Deskjet 710C), but despite trawling through the set up pages can't find anything amiss. Any suggestions would be appreciated greatly!