what factor can cause http 400 on one Jboss AS7 server but not on another with same war file?

[wheretogo]

The http 400 error from this problematic server is actually:

The request sent by the client was syntactically incorrect

It is unbelivable because this error pop up just when the user submitting a form to the server, so it is all POST request but not GET

then I rule out any encoding issue (I guess)....The post request including serveral string object and a java.util.Date object that's it.

But at this point I cannot really think of anything else related to the application itselft because same war file deployed on another server(same JBoss edition) works just fine....

Please share any ideas, thanks in advance.

[nickarls]

Can you capture the http requests completely (network level) and compare them?