Speedtester gone a bit mad?

[#1]

From today the speed tester has started giving download results higher than my IP profile 
Everything seems to go OK up until the very end when the reported speed jumps, eg from around 3300kbps to > 3600kbps. As my IP profile is 3500kbps this seems a bit weird.
Browser is Firefox(3.0.3)  on Gentoo Linux with flash version 10.0.12.36.
Anyone else seeing anything strange?

[#2]

mod:note
Moved to a more appropriate forum to get a response.

[#3]

Seems ok for me -
[quote author="BT Speedtest"]Test1 comprises of Best Effort Test:  -provides background information.
    Your DSL connection rate: 3648 kbps(DOWN-STREAM),  832 kbps(UP-STREAM)
    IP profile for your line is - 3000 kbps
    Actual IP throughput achieved during the test was - 2735 kbps
Perhaps just 'one of those things', is it still doing the same now?

[#4]

Are you on RIN?
If your answer is "What's RIN?" that's probably a no

[#5]

(I should have mentioned this was the PN tester at http://www.mybroadbandspeed.co.uk/ ; - and for jameseh I'm not on RIN)
And today I've done a couple of back-to-back tests and it 's reporting 'normal' speeds again so I guess I'll put it down to one of those things:)
Thanks for the responses guys.