[KoolKat]

Is one of your settings (u-torrent/router) set at randomize port and thus goes out of the others "range"?

To throw a long shot possiblity in

In U-torrent click options>preferences>connections.
Set "Listening port" to one chosen number and uncheck the randomize each start up.
Then>
In your router ,set your port range etc for U-torrent program ,and then to interperate that port range to the number you entered in U-torrents Listening Port section.

If all is green then ,then Lynnes tracker likes a lot of coffee hehe.

K_K