Background in PDF print quality

We're using Acrobat 6.0 Pro to create a document that is fed data from XML. The document is actually a check so we have a background applied that has all of the boxes and columns. The data that is filled in the form fields prints fine, but anything on the background prints slightly gray or not has high quality as what's in the form fields. The background document is a PDF that was created in InDesign. Is there anyway to improve how the document prints? When the background is printed alone, it prints fine.