One of my users is trying unsuccessfuly to access from behind a Bordermanager 3.7 proxy.

The error message in IE is "The page cannot be displayed." In Firefox,
the result is a BorderManager screen that reads, "HTTP Error, Status :
503 Service Unavailable Description : The requested method is not allowed
on this scheme type. Tunneling through the port being used is not allowed
Note : If necessary, please contact your Systems Administrator for

I am guessing that the problem has to do with the fact that he is
attempting to make an SSL connection over a port other than 443, but what
is the solution?