Keef,
I don't use skype, stay well away from it due to various security concerns.
However, having played with the software briefly on a few computers of late, I've noticed that it has UPnP enabled by default.
Kill that off and see how things look ? (hidden away in settings screens)
Also try Googling for info on Skype registry keys, particularly the supernode one(s) ... I'm not going to type links or registry keys here because I don't want to be blamed if you mess with the wrong bits of your registry.
