Number of problems with printing overlays

I am quite new to the idea of printing overlays and as expected I am running into a number of problems. How is it that after uploading a certain .PRN to the AS400 and creating an overlay then printing the overlay form the data has been realigned differently from the one I had just before allowing the program to print? Before, I had to change the overlay which happens to be a contact number in MS Word 2003. Can some please help me figure out why this overlay is being aligned to the left and how to correct this?
