Speeds are now back up to 6500Kbps without me altering anything. Had an engineer today who says line is one of the best he's seen going on lack of errors, noise margins etc so must have been an ISP fault somewhere along the line. Anyhow I'm now happy with the outcome and thank BTcare etc. Just hope others who're experiencing problems get them resolved OK.

if your sync speed an dprofile are fine but throughout is 200-600kbps this is highly likely to be a VP issue. On a max circuit connected 2048-8128 with a BRAS of 1750-7150 then the lower limit for BTWS to investigate is 600kbps as achieved on the bt speedtester

Haven't a clue what you're on about Abigail! I just know that everything is now running fine with btspeedtester giving over 6000Kbps, so I'm happy. Thanks for the reply though and have a great New Year.