Can't precisely center image on greeting card in CS2

In CS2 I have set up a 10x7 template. I have set up guides and have locked them. I have also locked the layer that the photo is in.

I have tried the align command. My image on the 10x7 folded greeting card(finished size is 5x7) is always off by a very small amount (1/16th of an inch, maybe 1/8th).

I have sized the image to fit exactly in the guide lines and it still is not perfect.

Is it possible to do this in Photoshop?

Thanks for any suggestions

What printer?

You are probably running into "gripper edge" problems especially if its an inkjet printer. The paper is automatically offset by the printer so that the printer has room to grab the edge of the paper to feed it through the machine. With Epsons you can pull some tricks with Center image and widest margins to compensate...