Anyone else had problems once BT have "upgraded" the broadband?

Our broadband was fine. Until Monday last week, when BT upgraded the local exchange to 21CN. Since then, our browsing speed has definitely been slightly faster. But we can't download anything. And I mean anything. I can't run any of the various speed tests, because they rely on downloading a file of a certain size to calculate the speed. I can't even run the Windows Update, but I can browse happily enough (obviously - I'm browsing now) and email works fine. It isn't PC related because my laptop and Wifey's netbook are suffering the same problem and even my PS3 won't update it's software.

Anybody got any ideas? The guys at Virgin haven't got any (and that's not dissing them because in general I've found them very helpful) and I'm stumped.

6 weeks ago I upgraded from option 1 to option 2. Broadband speeds in my area have never been great but BT told me they had new technology at the exchange that would allow download speeds of up to 8 meg. However due to distance from the exchange my speed would normally be between 4 and 8 meg.

To date the best speed I have achieved has been 728KBPS. I have been in regular contact with them and reminded them that they are in breach of contract for failing to provide the stated service or anywhere near what they have suggested. Suffice to say I'm not best pleased.

One of the things I have noticed is that I am unable to upload pictures in forums. I tried here yesterday but constantly get server time out messages.

They have told me that it's because the IP profile at the exchange is unstable and is continually degrading and that's why my speed keeps slowing down. I must have phoned them at least every other day. They tell me that will call back but never do, last night they admitted that notes have been put on my account screen reference my continued problems but as yet they haven't actually done anything physical about it.

I will check again tonight. If it's still slow I think I will be on to them again and terminate the contract with a view to finding an alternative provider.

IMO BT like to string customers along and tell lies. I would not recommend them to anybody else.