I'm sure someone will correct me if I'm wrong, but I don't think many ISP's offer static IP addresses. It's quite common (and perfectly normal) for it to change.
If you are running some sort of server and need a static address you could always use a free service like
DynDNS which can be re-associated with a new IP address as and when required.
Unfortunately most broadband is now sold as 'up to' and there's quite a few factors that can effect your overall speed. It may be the server that you're downloading from wont, or can't, supply the data fast enough for your connection - In this case it isn't Virgins fault. Have you run a few different speed tests or downloaded any test files?