When creating mailing labels, the print settings must be correct before sending the labels to the printer. If not, the labels will not format correctly when printed.
If you are having trouble printing your mailing labels, check the following settings in the System Reports > Setup (tab) > Mailing Labels for the mailing label that you are using. This example is a guideline for all mailing labels, but are more specific to Avery 5160 Mailing labels.
Depending on the type of font you use, you may have to adjust the margins to fit your text. If you are still having issues when printing the labels on 5160 sheets, then you may need to adjust the "Page Scaling" from the Print Options when printing from Adobe Reader. Using "None" for the "Page Scaling" usually works best.
Note: There are different versions of Adobe out there, so if these instructions don't work for you use the Adobe "Help" and search for the word "Scaling" for more assistance.