Ports for uTorrent

[#1]

Can someone please explain why each time I try to download something via uTorrent all the ports I attempt to use are closed.  No matter what number I enter it still comes up with "Port doesn't appear to be open".  Is there some special port number that I need to enter into uTorrent to enable the ability to download?
The weird thing is, sometimes it works perfectly and everything is green.  Yet 90% of the time it's red and I can't download anything.  Don't ask me to open the ports on my router as I'm not using one, I'm using the Voyager105 modem.  Also, firewall on or off it's still the same story.

[#2]

what does it say about 6881?

[#3]

The same as the others for now, "This port appears to be closed".  However, tomorrow it'll probably be fine.

[#4]

IT doesn't explain the intermittent nature of the problem, however how have you got our Firewall configured in the Member Centre?

[#5]

The PN firewall is turned off, like it's always been.

[#6]

Have you actually checked it though - just to make sure that its not managed to turn itself back on again? Or did you assume it was off because you never turned it on?