I've configured IBM Proxy on port 80 in front of a WAS 6.1 app on port
9081 (for testing purposes, a cluster with just 1 server). Whenever a
client request HTTP/1.1 with Accept-Encoding: gzip, WAS may respond
with gzip-ed data sent back to the proxy. In this case, proxy throws
Error 500.

E.g. IE7 request as follows:

GET /mywebapp/index.htm HTTP/1.1
Accept: */*
Accept-Language: de-at,en;q=0.5
UA-CPU: x86
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET
CLR 1.1.4322; InfoPath.1; .NET CLR 2.0.50727)
Host: str002
Connection: Keep-Alive
Cookie: owc_version=11; locale=de; TE3=N0:E N1:E N2:E N3:E N4:C N5:C
N6:C N7:C N8:C N9:C N10:C N11:C N12:C N13:C N14:C N15:C N16:C N17:C
N18:C N19:C N20:E N21:C N22:C N23:C N24:C N25:C N26:C;

WAS responds:

HTTP/1.1 200 OK
Content-Type: text/html; charset=UTF-8
Content-Encoding: gzip
Content-Language: de-AT
Set-Cookie: JSESSIONID=0000PxWjwDtiPt5zZsSD9CdlKC3:-1; Path=/
Transfer-Encoding: chunked
Date: Mon, 16 Jul 2007 07:32:06 GMT
Server: WebSphere Application Server/6.1

Proxy rersponds:

HTTP/1.1 500 Internal Server Error
Server: Proxy/1.0
Content-Length: 94
Connection: Close
Date: Mon, 16 Jul 2007 10:07:47 GMT
500 Internal Server Error

500 Internal
Server Error

What can I do to get this working (except from switching web browsers
to HTTP/1.0 so they won't request Accept-Encoding)???