Hey Guys, please don't argue! Don't worry Sphinx, I'd never disable all my firewalls and I have NAV running.
My router is a Netgear DG834G 54mbps and after reading some of the postings on the link I'm inclined to think that it might well be blocking incoming connections but not all of them, as I had about 4 completed uploads yesterday and 5 interrupted uploads.
Norton's alert logs do seem to be tying in with attempted uploads so I think it is stopping them and I've been trying to explain the problem to Symantec but they've just given up/got fed up and referred me to my supplier!
BTW I'm a 'she'.