The PM is perfectly explained by Erik.
Frank Abramonte:However, I exported individual pages to PDF in Quark 8. I then merged them into one PDF document using PDF Merge software.
This is almost certainly the cause of your problems.
Each individual page gets a subset of your font. When you merge the pages, the software is assuming the subsets are actually the same and not using all of them, or encoding them so that the printers RIP assumes they are the same. If you create individual PDF pages then don't try and merge them back into one file, just name them clearly and let the printer do it.
Frank Abramonte:When I saved the individual pages I chose to embed all fonts on each page. Does that mean only the Helvetica in use on that particular page, or ALL meaning all the Helvetica weights?
I still don't understand why a printer needs fonts over and above those actually being used on page.
ALL in the quark menu means only that you are not choosing to specifically exclude a font.
A Subset of each font on the page only includes the glyphs (letters, numbers) used in the page so if you used a headline in Helvetica Extra Bold that read DOH! and didn't use Helvetica Extra Bold elsewhere on the page then the Subset only includes 4 glyphs D, O, H, and !
If you used Distiller and avoided subsets then the whole font would be embedded so even though you only require DOH! you get the lot. When two or more of these PDFs are merged then the assumption that the software makes that these are the same font is true so the problem is avoided.
Its not that the Printer needs fonts or glyphs over and above those actually used on the page but the final merged pdf must be created in a way that actually uses those resources correctly.
... there was the puzzle of why the sun came out during the day, instead of at night when the light would come in useful.
Terry Pratchet