Sorry for the delay in response - it's been somewhat hectic here!
That link to spyguard brings back a blast from the past to me.
Investigation into my speedtouch 330 modem shows that the opening of the virgin home page is programmed in - by virgin, and there is no real way to do anything with their programming. It doesn't, however, mess up my normal 'about blank' default or anything.
So, I shall bear with it until more pennies are available and I can afford a decent router/modem such as Linksys or Voyager and the new rules on MACs and changing ISPs comes into force in a few weeks time.