I had OWA on 2003 standard, which was working fine (with SSL).
I made some changes, and now when I try to access I get loading... forever. (also from the server itself)
The changes I made that might cause the problem:
1. This server is no longer a DC.
2. I've upgraded the server to 2003 enterprise.
3. I've deleted the certificate and created a new one (but I get this problem also after disabling SSL so I guess it doesn't matter).
I've deleted the virtual directories and restarted exchange services to let them be created again.