ISA 2006 Leaking internal IP address

Hi all
I am using ISA 2006 EE to securely publish a site and terminating SSL at the
proxy, so it looks like this:
Client <--https--> ISA 2006 <--http--> internal server
On the listener properties, I have the "connections" tab set to enable both
port 80 and 443 and "HTTP to HTTPS redirection" set to redirect all traffic
from http to https (the bottom option)
On the access rule, I have the bridging tab set to redirect to port 80 on
the internal web server. This is all working fine.
However, if you connect to the ISA 2006 server port on port 80 and issue the
following request:
GET / HTTP/1.0
ISA replies with a 302 Object Moved and another header of "Location:
https://internal_ISA_IP_address/"

Does anyone know how to prevent ISA leaking its internal IP address?

I suppose I can configure the listener to not automatically redirect the
request, but I'd much rather leave it on.

Thanks