could not read from statistics collector pipe, Windows 2000, PostgreSQL 8.0.1

We are running PostgreSQL 8.0.1 since last week and have these
messages in our PostgreSQL log file:

The first time we get the error approx 1/2 hour after restarting PostgreSQL, it is:

FATAL: could not read from statistics collector pipe: No such file or directory
LOG: statistics collector process (PID 1628) was terminated by signal 1

and then a couple of time every hour, we get:

FATAL: could not read from statistics collector pipe: No error
FATAL: could not write to statistics collector pipe: No connection could be made because the target machine actively refused it.
or:
FATAL: could not read from statistics collector pipe: No error
LOG: statistics collector process (PID 1628) was terminated by signal 1

Our application seems unaffected by these messages.

We are on Windows 2000 Server, Service Pack 4 and
were successfully running PostgreSQL 7.4.1 before that.

Is this normal and if not, how do we fix that?

Thanks
Jean-Pierre Pelletier