Unknown winsock error 10061

Hello,

PostgreSQL 9.0, Windows 2008
32 different PostGIS Databases
round about 20 active connections by duration
max_connections = 100
Memory load around 30%
CPUs load around 50%
Network load less then 20%

No firewall installed at all

Randomly there is the message in log:
could not receive data from client: Unknown winsock error 10061

After restart - the first 10-15 minutes are ok - but then the messages start
sometimes 3 within a minute, sometimes minutely then again all is fine
for 5 minutes
then 7 or 8 messages secondly - minutely and so on.

less messages during night - more messages during day - but usually
during nights
there is very rare traffic.

It isn't a connection from a special tool to a special database creating
the message.

The failing connections are to different databases and from different
users. It can be
a pgAdmin connection or a connection from an application. It is totally
random.

Max connections isn't reached at all - neither network nor CPU nor RAM
are overloaded.

What else could create that issue?
How can I solve the issue?

Best Regards,

Susanne

--
Dipl. Inf. Susanne Ebrecht - 2ndQuadrant
PostgreSQL Development, 24x7 Support, Training and Services
www.2ndQuadrant.com