Me too. . .
I ran into the same problem with drop shadows on a placed illustrator, but I've seen it on text before too. Printing to postscript and using the Acrobat 5 setting through distiller didn't help. BUT when I exported straight from InDesign with the Acrobat 5 setting is worked.
I have a client who with no imagination (like most). He can't see beyond the white lines when viewing the PDF I sent them. I know they won't print, I've told him they won't print, but he wants it as a PDF and wants the lines gone.
So sometimes you need them to not be there.