Sorry to be replying to my own request for help, but as usual I found a
"fix" about 2 hours after posting the question!
As mentioned previously, I had just used the "TrueType Fonts on Debian
XFree86 4.x Systems" HOWTO by Paul D. Smith to enable TrueType Fonts on
my Debian "testing" system running XFree86 version 4.1. While poking
around the various logs, I discovered that both XFS and X were
complaining that the 100dpi and 75dpi fonts were "unreadable" and ALL
references to them in the X "Font paths" were being removed from the
list of available fonts. In the HOWTO, section 5.3 "Aliases for
Helvetica" the "fonts.alias" files for both were modified to improve the
rendering of Helvetica fonts. Removing these changes restored the
system to "normal" and both XFS and X quit complaining. The font size
"problem" in NS Mail disappeared. NOTE: NS Mail was the ONLY app that
appeared to be affected here.
All is well now as far as I can determine here. I would suggest making
the changes for the Helvetica Font with care....possibly saving this to
the last step. I don't know WHY the recommended changes mess up the
100dpi and 75dpi fonts on my system, but they did.
Submitted for the Mailing List info and consideration.
Cheers,
-Don Spoon-