It seems to me there is a bug in SIP Configuration wizard.
Registrar "Port" field is currently ignored.
How to reproduce:
1. Add new SIP account.
2. Select Advanced wizard, enter your account details.
3. Switch to "Connection" tab and enter non-standard Registrar Port
(5566 in my case).
4. Click "Next"
Current behaviour: Jitsi ignores Port 5566 and sends traffic to port 5060
Expected behaviour: SIP traffic sent to port 5566
Tested with SVN code rev. 8777