Some speed testers measure the download speed and the upload speed and then add them together which could give you an average reading of about 500 to 600 Kbps. This one click here will give you both speeds separately which should be approx 970 for download and 90/100 for upload. Hope this helps.
I never asked them to upgrade mine, they just did it automatically and I didn't get a password to use. I would think that the basic broadband for NTL is now 1Meg. for everyone. Mine doesn't seem to be capped either.
Im on NTL,just tried the test Wak suggested,and i got 964.96 for download and 118.48 for upload.I read months ago on NTL site that it would have a cap when it changed to 1mb.Mine has changed by the look of it,but ive had no email or letter.I think i would change if it did.