Table headers go missing when I compile a .PDF

Please. May I ask for assistance! I am creating a .Pdf on a Windows XP platform using Quark Express version. 8.01. When I compile the data sheet through Acrobat Distiller (version 8.1.0) and Acrobat Professional (version 8.0.1), then finished .Pdf has missing column headers from tables in the data sheet. (My Acrobat Reader is version 9.44).

Column headings are shifted over, in some instances. Only headings; table content is not affected. White blocks appear to the left of the first column header missing. And this block out other readable text on the page.

Any suggestions on what is going wrong? Or what I can check to prevent this? (Thank you in advance for your help. It's driving me crazy!)

On the attached .Pdf, column headers should appear in the left hand column on each line under Sensing Input, Power Input, Voltage. But they don't.

Ron