You have to open the appropriate port on the machine you want to remote
into. 590x.

Does ubuntu remote viewer use a odd port? I have realvnc on XP working
right now just fine.

I'm thinking that the firewall on Ubuntu closes the port. I think it's port
5900.

Yea, I have that open.

Your talking on the viewing I have 5900 & 5500 on both machines open.

Then you've surpassed my skill set.

At least we are thinking along the same lines.........

I'm not sure what you're trying to do, but you could SSH to the machine
using PuTTy or something like it. Again, you'd have to make sure the ports
are configured properly.
Or you could go straight command line with:

ssh [username@remotehostnameoripaddress],
use -p [portnumber] if you have sshd setup to listen on a port other
than 22. You will be prompted for password.

if you need remote copy:
(from local machine)
scp [username@remotehostnameoripaddress:remote/file/name]
[local/target/directory]
use -P [portnumber] if necessary, -r to copy a directory recursively.

check the man pages, but I think that's the syntax.

Had to mess with this lately and found this post:
ubuntuforums.org/showthread.php+change+port

I was not trying to set up a network or anything just trying to record a
flash of what was happening on the screen. Maybe someone could recommend
a flash recorder to complete my job, though what I did worked.

I checked this out and unfortunately it didnt help.
But, while I was checking it out, I was just clicking around on Remote
Viewer and all of the sudden it connected. No idea why. I signed in and
it did connect.