Yea, thats what happened to me. On the day of the migration the phone started acting odd by continuous ringing and knocking me offline.
Had an BTO engineer came out, isolated the issue and they said it seemed to be Sky's equipment. This engineer didn't report it to Sky, and after a few tests the phone line ended up dead and half the net speed.
Phoned Sky then BT (because they have my line rental), and arranged for this visit. The fault reporter initially was still saying it was in my property, even though it wasn't. Anyways the engineer who turned up today seemed to make a write up about an earthed line just outside of his reach. But he had identified it and added all the details to it, for the local BTO people to just do the job. Then local BTO people got the line back up, speed went back up.. but they called to check if it was ok and back to the long continuous ring. So he went back in to the exchange and said he found the problem on Sky's equipment. But he would need to request permission from Sky to replace it. 10 minutes later he called back saying they had given him permission and he had now changed it. So now all is working good.
So it WAS Sky's equipment that started all this. I think the cabinet line was kinda a side issue. My speed as improved since this as been done. The exchange part with the continuous phone ring started during the Sky migration.
I wonder if Sky need to run some kind of checks of their equipment. It's only going to be them that get a bad reputation if they don't do something.
Demon => Freeserve => Pipex => Be => Sky