Sorry for delay in reply, my internet is not the most reliable and had an outage, just to add to the rubbishness.
Yes, provided by Sky, and it's a nightmare. (Is BT worse?)I'm running 10,6,8 still on SL. It's definitely the MBP because there are instances when I'm in the usual place it connects, and it just won't for several minutes. And then the iPhone, now running iOS 7 did pick it up, but that's much more unreliable than the MBP. It's appalling how that drops it, even more than my iPhone 4, which was horrendous, but not as bad as this 5S is.
r0k, I'm not sure about all those answers as it's a fair while since I set that up, but will check. I know the router may be a bit past it, by a year or so, but I don't get these problems on non-Apple products, and that was my point really. It's a shame that none of them can hold on to a signal. Downloading is a nightmare because I always have to have a few attempts at it, because it will always cut out at some point. I have tried various different channels over the year but it's made no difference at all.
Replacing the router is a no no with the ISP, no idea why, but if you think it may do the trick, I'm open to that.