Just from a quick Google search, at least one other person finds they're being hit by the FUP outside of the normal hours
Tiscali Forums - Can I get fup'd outside peak hours.

Maybe if you have a look around that Tiscali forum, you'll find some more info.

Some Tiscali users have been able to connect after changing ports. In LW go tools > options > advanced > firewall config. There you can change LW's listening port. Try port 64049 (or something in the range of 49152 - 65535). No guarantees that it'll help, but it's an easy thing to try

If you have port forwarding set up for a modem/router, the port forwarded will also have to change!