Sorry, bit late on this thread. I've swapped a regular Sky box for a Sky+ without any problem. You need two RF feeds from your dish to the Sky+ box - hence the 'dual LNB'. Your Sky card and box are 'paired' but this can be changed with a phone call to Sky - if they ask, just tell them your old box was faulty and you've been given a replacement from a family member. If your original Sky box is over 12 months old you own it, and can replace it with whatever you want...

It was a few years ago when I did ours and at the time to get Sky+ working you have to subscribe to the service - for us it was already included in our program bundle; I'm not sure what the current situation is, but again I'm sure it's just a phone call to Sky to set this up if you need to.

HTH, Pete

Sky+ is now free for all subscribers.

I did this a few months ago, as our box had stopped working, and I got my dads old Sky box, but the nice Sky people said they couldn't do it and would send me a brand new box instead...

Obviously you got through to one of the more helpful people who work there...