Penetration Testing: Raptor firewall 6.1 port 80

[Martin S <shurbanm () vu union edu>]

I am testing a couple of Raptor firewalls (6.1 apparently). And I ran
Brutus on port 80 just to see what's going to happen using Forms
authentication. It does pick up 2 successful authentications using (admin
and backup as logins). However, this cannot be right as first of all it
picks up different passwords (like aaa or academia on different runs) and
secondly a web browser session on port 80 comes back with:
"
Service Unavailable
The proxy is currently unable to handle the request due to a (possibly)
temporary error. Extended error information is:

If this situation persists, please contact your firewall administrator. "

Any ideas?