Run in the last few seconds. No request about the certificate.

Download speedachieved during the test was - 30 Mbps
For your connection, the acceptable range of speedsis 12 Mbps-38.72 Mbps .
Additional Information:
IP Profile for your line is - 38.72 Mbps

Upload speed achieved during the test was - 1.76Mbps
Additional Information:
Upstream Rate IP profile on your line is - 2 Mbps

Still not working for me

Looks as though it's geographic then? For reasons you know .

I just tried it and get a page showing:
HTTP Status 404 - /cgi-bin/home.page.pl
The address bar shows: 'Apache Tomcat/6.0.16 Error Report'

What URL are the failing people using? I use
http://speedtester.bt.com/

Download speedachieved during the test was - 26 Mbps
For your connection, the acceptable range of speedsis 12 Mbps-38.72 Mbps .
Additional Information:
IP Profile for your line is - 38.72 Mbps

Upload speed achieved during the test was - 1.81Mbps
Additional Information:
Upstream Rate IP profile on your line is - 2 Mbps

I was using a saved link to the page, and it was:
http//speedtester.bt.com/cgi-bin/home.page.pl
I used it just a few days ago and it worked as usual giving the same results as I had a couple of weeks ago.

Now I just used the link you posted and it went to the page, gave a security notice that the cert was passed and I went ahead.
The test completed without showing the stages as it always had before, and very quickly showed me the whole test result - and it showed faster down/up speeds than it ever had previously (6382/911). The actual line profiles were identical to before though:

Download Speed
6.82 Mbps

0 Kbps 7.15 Mbps
Max Achievable Speed

Download speed achieved during the test was - 6.82 Mbps
For your connection, the acceptable range of speeds is 2 Mbps-7.15 Mbps.
IP Profile for your line is - 6.88 Mbps

2. Upstream Test: -provides background information.

Upload Speed
1.03 Mbps

0 Kbps 832 Kbps
Max Achievable Speed

Upload speed achieved during the test was - 1.03Mbps
Additional Information:
Upstream Rate IP profile on your line is - 832 Kbps

We were unable to identify any performance problem with your service at this time.
It is possible that any problem you are currently, or had previously experienced may have been caused by traffic congestion on the Internet or by the server you were accessing responding slowly.
If you continue to encounter a problem with a specific server, please contact the administrator of that server in the first instance.

We have identified that you have additional services enabled on you broadband line, please click continue to run advanced service tests.

Not sure what those 'additional services' are though - we don't have the Sky box connected to the phone line.

I think that Additional Services detection is a bug. I get it as well. Clicked it one time and it fell over because I haven't any.

The main one is Assured Rate, for BT Vision and similar services, so you should get the assured rate through the whole BT Wholesale network for them.

Neat!

Upload speed achieved during the test was - 1.03Mbps
Additional Information:
Upstream Rate IP profile on your line is - 832 Kbps

Both:

http://speedtester.bt.com/

http://speedtest.btcentralplus.com/

with exactly the same result!

Umm :.

The bt central one just ran the download then gave

Alert

The browser session has timed out. Please refresh the main Performance Tester page.

Clicked your link again and this time

Download speedachieved during the test was - 33 Mbps
For your connection, the acceptable range of speedsis 12 Mbps-38.72 Mbps .
Additional Information:
IP Profile for your line is - 38.72 Mbps

Upload speed achieved during the test was - 1.77Mbps
Additional Information:
Upstream Rate IP profile on your line is - 2 Mbps