Each time any user tries to access any Internet resource for the first

time after each login they get this error message:

Not Found
The requested URL /BM-Login/ was not found on this server.

Apache/1.3.27 Server at border_server.westerngraphics.org Port 443

Immediately re-attempting to access the very same resource is
It continues to be successful until the next time they log out and
login again. Any ideas on what might cause this?