[JIra - WebSeal] Timout when attaching a document to issue

When I try to attach dokuments during the busiest working yours - the most network traffic - I have problems attaching dokuments to issues i Jira.
In front of the Jira Server is a WebSeal server - which gives the error message:

*******************************************************************
0x38ad5420 (950883360) Could not write to socket

Explanation: This is used only as an internal error code. It represents that WebSEAL was unable to write to a junctioned Web server, or to a browser.

Action: No action required.

Name: iv_s_socket_write

Severity: Error

Component: wiv / ivcore_s_sock
*******************************************************************

It says it was unable to contact the Jira server.

I get the following stacktrace from the Jira Server log on WAS:

[1/13/06 13:56:21:080 CET] 6b7cb0dd SRTServletReq E SRVE0120E: IO Error java.io.InterruptedIOException: Read timed out
at java.net.SocketInputStream.socketRead(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java(Compiled Code))
at com.ibm.ws.io.Stream.read(Stream.java(Compiled Code))
at com.ibm.ws.io.ReadStream.read(ReadStream.java(Compiled Code))
at com.ibm.ws.http.ContentLengthInputStream.read(ContentLengthInputStream.java(Compiled Code))
at com.ibm.ws.io.ReadStream.read(ReadStream.java(Compiled Code))
at com.ibm.ws.webcontainer.http.HttpConnection.read(HttpConnection.java(Inlined Compiled Code))
at com.ibm.ws.webcontainer.srp.SRPConnection.read(SRPConnection.java(Compiled Code))
at com.ibm.ws.webcontainer.srt.SRTInputStream.read(SRTInputStream.java(Compiled Code))
at com.ibm.ws.webcontainer.srt.http.HttpInputStream.read(HttpInputStream.java(Compiled Code))
at java.io.InputStream.read(InputStream.java(Inlined Compiled Code))
at com.ibm.ws.webcontainer.srt.SRTServletRequest.finish(SRTServletRequest.java(Compiled Code))
at com.ibm.ws.webcontainer.srt.SRTConnectionContext.finishConnection(SRTConnectionContext.java(Compiled Code))
at com.ibm.ws.webcontainer.srt.WebAppInvoker.doForward(WebAppInvoker.java(Compiled Code))
at com.ibm.ws.webcontainer.srt.WebAppInvoker.handleInvocationHook(WebAppInvoker.java(Compiled Code))
at com.ibm.ws.webcontainer.cache.invocation.CachedInvocation.handleInvocation(CachedInvocation.java(Compiled Code))
at com.ibm.ws.webcontainer.cache.invocation.CacheableInvocationContext.invoke(CacheableInvocationContext.java(Compiled Code))
at com.ibm.ws.webcontainer.srp.ServletRequestProcessor.dispatchByURI(ServletRequestProcessor.java(Compiled Code))
at com.ibm.ws.webcontainer.oselistener.OSEListenerDispatcher.service(OSEListener.java(Compiled Code))
at com.ibm.ws.webcontainer.http.HttpConnection.handleRequest(HttpConnection.java(Compiled Code))
at com.ibm.ws.http.HttpConnection.readAndHandleRequest(HttpConnection.java(Compiled Code))
at com.ibm.ws.http.HttpConnection.run(HttpConnection.java(Compiled Code))
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:672)

[1/13/06 13:56:25:475 CET] 1f55b0d8 OSEListenerDi E PLGN0021E: Servlet Request Processor Exception: Virtual Host/WebGroup Not Found : The web group / has not been defined

The version info:
was v5.0.2
OS AIX 5.1