iPhoto 11 / printing help please

[Ruffian829]

I've realized that even when I crop my photos to a 4x6 size in iphoto, when I print them out they still get cropped again in the printing process. I hate this, because I try and crop them before hand to make sure they are cropped how I want and not just taking a chunk off the top and bottom equally.
Does anyone have any idea why this is or how I can fix it?? I'd like to get some of these pictures printed out better than this...
Is it possibly a printer problem? (I'm not going through the printer software, but selecting the photos and pressing print in iphoto. I check the preview and the pics appear as I cropped them, when I actually print them, they are zoomed in more and I lose more of the top and bottom).

Thanks!!