in the end my question is ... how do i even debug this?

i have an EAR that currently deploys and runs in JBoss 4.0.4.  my task - get it to run in a copy of JBoss 4.0.5 setup by another company (it's running their application and they want us to just deploy our EAR in their copy).  i have the EAR in the deploy folder along w/ the DB, properties and login-config.xml configured, libs in the server\default\lib that we need ... along w/ our JBoss SX JAAS login module.

in JBoss 4.0.4 (the one that works)...

1) EAR deploys

2) enter URL ... access log shows HTTP response of 302 (redirect)

3) login screen displayed

in JBoss 4.0.5 (the one that isn't working)...

1) EAR deploys.  there are no errors in the log files.  there are also background threads that run and log information and we see this

2) enter a URL ... access log shows HTTP response of 302 (redirect)

3) no login screen; rather IE displays "page cannot be accessed"

if i enter a URL directly to my login.jsp (outside the security  boundary), it gets compiled (we see java and class files in tmp folder)  and displays.  therefore, i've ruled out a compilation problem.

i've also had discussions w/ the company re: if there were any modifications to the standard jboss/tomcat configuration that might restrict something - they replied no.

i've turned debugging on in our application, our login module, for "org.jboss" and in the tomcat web.xml to see if i could get any helpful information - nothing is being logged except for what is in the access log and this ends at the HTTP response of 302.

i've visually inspected ... the WAR jboss-web.xml referenced security domain properly maps to the application policy in login-config.xml.

at this point i'm at a loss of what to try next and i'm in a time crunch which doesn't help matters.  is there something else i can turn on to debug to determine to what is the HTTP response being redirected to and why it isn't finding it?  any other suggestions?

also please note, the environment in which i'm doing this is very restricted (e.g., no dev tools available).