Web Server problems

I have been having a new problem as of late and was wondering if anybody
else has had a similar issue.  For some reason when one of our client apps
makes a request to our Apache web server it brings it down.  The problem
doesn't have any consistency to it.  Most times the client app works, but
every once in a while this happens.  The jobs all look fine, but it just
stops working.  I have to end the server and bring it back up.  I don't know
if bad packets in the request could cause something like this or not, but I
figured the web server could handle something like that.
 
Here's the error log:
[Mon Dec 22 11:51:13 2003] [error] [client 172.25.138.235] ZSRV_MSG0577:
translation filter - incomplete character at end of input - 
[Mon Dec 22 11:51:13 2003] [error] [client 172.25.138.235] ZSRV_MSG0577:
translation filter - incomplete character at end of input - 
[Mon Dec 22 11:51:21 2003] [error] [client 172.25.138.235] ZSRV_MSG0577:
translation filter - incomplete character at end of input - 
[Mon Dec 22 11:51:23 2003] [error] [client 172.25.138.235] ZSRV_MSG0577:
translation filter - incomplete character at end of input - 
[Mon Dec 22 11:51:23 2003] [error] [client 172.25.138.235] ZSRV_MSG0577:
translation filter - incomplete character at end of input -