7.1 ... wtf?

Hi again,

sometime ago i had a post on 7.1 performance .. this is still up-to-date
cause the performance is bad like hell but i have a little bit bigger
problem now. I have a dual p3-1ghz + 1gig ram. The hardware is new (asus
dual board + registered ecc sdram) and is quite nice but postgres7.1 seems
to mess up with it. I have no idea why, but the server kills himself every
now and then. the load goes up to 50 and then some minutes later its gone
(doesn't respond to ANY cmds, no ssh, no shell). i always have to reset it.
the only thing i found pointing me towards postgres are these error messages
when surfing the pages which use the server as backend.

I get these errors in a random manner:

The System is in maintenance mode (something like that)
The System is in recovery state
The System is shutting down.
The System is going up.
Sorry, to many clients already (2 processes running / 64 max connections
configured)

Note: I do not restart the postmaster nor does any script. the system is
started and running .. why does he say "shutting down"?!! also the
performance seems to be really crap. (the database is currenly 80mb nothing
THIS server should worry about).

any help?

thank,
thomas