postmaster switches

At first I thought this is a portability issue, but then since I got a lot of regression tests
ok on AIX 4.2.1 when starting postmaster without switches, I now think this is a general problem
of the current CVS tree.

When I start postmaster with:
postmaster -S -o '-B 2048 -F'

something seems to get messed up.
postgres dumps core on the first statement issued through psql.

Any ideas ?
Andreas