Another "PS" to this "man of worms" -oops- "can of worms"...
After having a closer look at my 6.0 system and my 5.5 system,
I noticed/recalled that MANPATH can make quite a difference. If
your system also has a man.dbz file in /etc as well as /usr/man,
then you might want to try these two variants:
shell/iX> unset MANPATH
shell/iX> man -M /usr/man tar
shell/iX> man -M /etc tar
The same test might also be "interesting" with man lp, for example.
Lars "don't shoot the messenger" ;-)
(considering export MANPATH=/usr/local/man:/etc:/usr/man for /etc/profile)