Open Ports on Router

Please re-direct me if this is not the correct NG. I am having a problem with random ports opening on my router. They are not firewall ports, they're on the virtual server (BT's version of port forwarding). I have a BT Voyager

2000 with one wired connection and one wireless (not a PC though, it's a freeview box we use to pick up e-mails). I have restricted the router to only ever giving out two IP addresses and both are used, the wireless device has one, my PC the other. I have also configured it to only accept the MAC address of the wireless device.

The ports opening are random, one udp, one TCP. Ports it has used recently include UDP - 10692; 13040; 10811. TCP - 14099; 8553; 15461. If I turn the PC off chances are they will be different next time I boot up. I have 128 bit WEP on.

Other details - I have run / running Panda Anti Virus, Norton AV, Microsoft Antispyware, Adaware, Hijack This and all have reported absolutely nothing out of the ordinary. I use MSN Messenger a lot and also use Real VNC but have paid for the encrypted version. Am I just being paranoid and they are just normal or can you recommend something else to try.

Thanks a lot for any help.

Paul.