I got the same problem with VNC.

Server on winXP desktop, test says it should work.
VNC viewer on N900, installed properly.

I connect either within the lan with the 192.168.0.xxx address or without the lan with the outside IP address.

Both tried to connect with and without the port. I opened the port in the router as well but still got nothing. Any tips?

edit: ping works btw from n900

Okay. Got It Worrking.
making Sure Encryption Is off Works For Me.
seems To Auto Caps Every Word After A Space Though :s