[Groff] inability to process german umlauts

[Jan-Herbert Damm]

Dear List,

if somebody can tell me where to start digging into the following problem i am
grateful:

I like to use "groff -mom" for typesetting. Recently i set up a new system
changing the  locale from iso-8859-1 to utf8. I use vim to write texts.
German umlauts now produce the following errormessages:

test.mom:136: can't translate character code 167 to special character `sc' in
transparent throughput
test.mom:139: can't translate character code 194 to special character `^A' in
transparent throughput
test.mom:139: can't translate character code 167 to special character `sc' in
transparent throughput
test.mom:139: can't translate character code 195 to special character `~A' in
transparent throughput
test.mom:139: can't translate character code 188 to special character `14' in
transparent throughput

The resulting ps-file contains unwanted combinations of characters mostly
containing an 'A' with '~' on top.

Processing a file backupped from the old system does not produce these
problems (vim's ":set all" output shows "encoding=utf8" there as it does in
test.mom here) 

My groff ist version 1.20.1 which i compiled after the generic groff 1.18.1
from my ubuntu 8.10 produced this encoding problem to begin with.

"$locale" outputs to:
LANG=de_DE.UTF-8
LC_CTYPE="de_DE.UTF-8"
LC_NUMERIC="de_DE.UTF-8"
LC_TIME="de_DE.UTF-8"
LC_COLLATE="de_DE.UTF-8"
LC_MONETARY="de_DE.UTF-8"
LC_MESSAGES="de_DE.UTF-8"
LC_PAPER="de_DE.UTF-8"
LC_NAME="de_DE.UTF-8"
LC_ADDRESS="de_DE.UTF-8"
LC_TELEPHONE="de_DE.UTF-8"
LC_MEASUREMENT="de_DE.UTF-8"
LC_IDENTIFICATION="de_DE.UTF-8"
LC_ALL=

I should add that i am haunted by encoding problems. I have incomprehensible
errors such as that if i put umlauts in my ".muttrc" the reply-mails in vim have
wrong umlauts but if the ".muttrc" is clear of umlauts everything is fine. Or
that a non gui-terminal (via strg-alt-f1) prints all umlauts exept small 'ö'
(oe) and small 'ä' (ae).

I am aware that this is a problem that might have been reported before but
i am unable to find answers since i can't pin down the problem in a sensible
way. And i am very frustrated.

Any hints welcome.

Jan

-- 
Time flies like the wind, but fruit flies like bananas.
(Dank an JP, ML mutt-users)