My speed has dropped by two thirds over night?!

[#1]

My download speed was 1mb yesterday and today it is 3 hundred k. I  have the 12 mb connection and in the email it was said that based on the distance from my house to the local exchange that i would get approximately 9 mb speed which i was very happy with. However i wake up today and see that it has dropped over night from 1mb speed to 3hundred speed. I followed the READ THIS FIRST thread and went to the bt speed test and got these results:
Download speedachieved during the test was - 3391 Kbps
For your connection, the acceptable range of speedsis 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :12232 Kbps(DOWN-STREAM), 444 Kbps(UP-STREAM)
IP Profile for your line is - 3500 Kbps
The throughput of Best Efforts (BE) classes achieved during the test is - 15.16:24.33:60.51 (SBE:NBE:PBE)
These figures represent the ratio while sententiously passing Sub BE, Normal BE and Priority BE marked traffic.
IP Profile for my line is 3500? What's going on with this does anyone know?

[#2]

Ok spoke to the tech guys and they said that because my line kept dropping off that the profile keeps moving down automatically because it thinks that the line is unstable. But it's because i've been resetting the router a lot to try and port forward, I told him this and he said to plug it into the test socket and do not turn it off under any circumstances if possible and it should automatically speed up again. Ok cool so i guess that's solved. Also fixed the port forwarding by changing back to my old router and had it set up within 5 minutes.