PostgreSQL on Potato installation bug?

[Erik van der Meulen <erik@avondel.xs4all.nl>]

I like to install PostgreSQL in order to get IMP working. If I do an
apt-get install postgresql the configuration script breaks with:

  Restarting PostgreSQL postmaster
  No /usr/lib/postgresql/bin/postmaster found running; none killed.
  Starting PostgreSQL postmaster
  ps: unknown long option
  usage:  ps acehjlnrsSuvwx{t<tty>|#|O[-]u[-]U..} \
             --sort:[-]key1,[-]key2,...
             --help gives you this message
             --version prints version information

I do not know what goes wrong here. Can someone provide a clue?

Thanks a lot.
				 
--
  Erik van der Meulen <erik@avondel.xs4all.nl>