Help! Trouble with paper size in PSCS2

I'm trying to print a 4x6 image on a stock card. The card measures 11.0 x 7.375. I made a new white background measuring exactly this size. Then I placed my image on to that background. In Page Setup, I made a new paper size for my printer exactly matching this size. Then to Print with Preview, Center Image checked, then Print. At this point I get a warning "The image is larger that the paper's printable area; some clipping will occur." If I then click Proceed, the page prints but the image is slightly off centre, by a couple of millimetres. Given the way I set this up, why am I getting that clipping warning and how can I fix this? Thanks.
dkd

You're forgetting the printer's margins. Does your printer have a "borderless" printing option? If so, try that. If not, determine what the margins are(should be in the manual), and create your document to fit within those margins.

Bodog, when I set up the custom page in Page Setup, I set the margins at 0 all around. I figure that should have taken care of it.

Another thing: In Print with Preview, if I check Scale to Fit Media, the Scale becomes 99.78%, the Height 10.972, rather than 11 and the Width 7.361 rather than 7.375. I'm not sure what this is telling me.

Setting margins to zero doesn't mean the printer can overcome it's physical limitations and print outside the margins unless "borderless is selected.