Nroff changes characters?

[greg at sdcsvax.UUCP]

I'm not a nroff wizard, so I thought I'd ask before I started plowing
through the sources.  I hope somebody has seen this before.

I made a new version of nroff (from the System V.2 sources).  I seems
to work OK, except that it converts all occurances of a capital "S"
into a capital "Z".  Thus, "System V" comes out "Zystem V".  It seems
to be the only character affected.  Can anybody tell my why this nroff
has a German (Polish?) accent, or failing that, where I should start
looking to fix the problem?  Tks.
-- 
-- Greg Noel, NCR Torrey Pines       Greg at sdcsvax.UUCP or Greg at nosc.ARPA