[groff] ps2pdf / Acrobat Reader problem

[Robert D. Goulding]

Hope this isn't a FAQ.  I'm having an odd problem generating documents by
the route:

groff (-ms) -> Postscript -> ps2pdf -> PDF

The postscript output looks fine; but in the PDF, viewed with Acrobat
Reader, little gaps appear after the `fi' ligatures.  These gaps are not
apparent with xpdf or gv, and Acrobat Reader *prints* the document
correctly.  I'm using the latest groff 1.18, GNU Ghostscript 7.05, Acrobat
Reader 4.0 for Linux.  Anyone else had this problem?

Robert.