I wander .... about Unknown error

Hello,

I have an application serving thousands of dynamic pages by day to
hundreds of users. The application talks to apache through a
proprietary module. Platform is w2k, see below apache version.

In last five years, only problem I didn't solve is the one I'm
referring now (I was never able to reproduce it to the application
provider customer service).

It's only a guess the three below messages could be related. Anyway,
when problem arises (four/six times by year), apache doesn't
connect(calling the application, status page for example is correctly
served and it allows to see the problem: I have 512 available requests
and I can see 512 requests waiting for an answer), the application
continues to "internally" works but it is not able to talk to apache,
waiting for answer.

Depending when I see the problem, I can solve it simply
stopping/starting apache, stopping/starting application too, rebooting
the system.

Apache is listening on std port 80, there is no other application on
apache, and apart tons of antivirus sw, there is anything else running
on the server.

Has anyone some hint?

Thanks a lot

AC

Server Version: Apache/1.3.37 (Win32)
Server Built: Jul 27 2006 15:23:00

[Thu Jan 04 10:43:46 2007] [info] [client xxx.yyy.zzz.11]
(10054)Unknown error: client stopped connection before rwrite completed
[Thu Jan 04 10:48:47 2007] [info] [client xxx.yyy.zzz.38]
(10053)Unknown error: client stopped connection before rwrite completed
[Thu Jan 04 10:48:47 2007] [info] [client xxx.yyy.zzz.38]
(10053)Unknown error: client stopped connection before rwrite completed

netstat -an
Active Connections

Proto Local Address Foreign Address State
TCP 0.0.0.0:21 0.0.0.0:0 LISTENING
TCP 0.0.0.0:80 0.0.0.0:0 LISTENING
TCP 0.0.0.0:135 0.0.0.0:0 LISTENING
TCP 0.0.0.0:382 0.0.0.0:0 LISTENING
TCP 0.0.0.0:383 0.0.0.0:0 LISTENING