Postgres is eating up all my memory

Hello List,

postgres 8.2 is not doing too much but eating up all my memory:
http://pastebin.com/m4cf22ee2
The postgresql.conf is at the very bottom of the pastebin.

I guess this is a configuration issue. The CPUs are almost 100% idle
but i seem to run out of memory.

Any idea what i could do here?

Cheers,
Mario