Test Drive on JBoss "Invalid message recieved with signature"

Hi,

I'm trying to get the testdrive application from http://coenraets.org up and running on JBoss ( 4.2.1.GA ). Looking in the logs the war file seems to be getting deployed correctly and its contents are extracted to tmp/deploy/tmp9203testdrive-exp.war. However, when I try and navigate to it in a browser the following error appears in the jboss logs.

[AjpMessage] Invalid message recieved with signature 18245

Does anybody have any idea on why i'm encountering this error?

Thanks!