Thank you both.
I knew roughly what ping was, but not how much it could affect pageloads, email etc at that level.
Bill, the interleaving happened right after the first BT fault repair caused a disconnection and didn't affect the SNR which was pretty close to what it has been for some time.
The second one for planned maintenance a few days later reconnected with SNR up of 14.6, and almost half upload speed.
Still, whatever or however I got reconnected that first time I ended up with interleaving which happened the day after on 3rd.
On both occasions the ping is showing between 45 & 55 ..unusual for my connection, but as you both say it's not likely to cause noticeable problems, then I'll not worry about it.
I'm still not happy that pre-olympics it was a better connection where I was connected though! Seems there's nothing they can do about moving those people back
I'll see how it goes now. It's seemed pretty much OK tonight.
Unless there's a reason, I rarely lose connection.