Slow speed tonight

[#1]

Hi All,
Having issues with speed tonight, only hitting 1/2mb as per BT speed test, my router is connected at 9579 and my BT profile is 8mb or so.
thanks

[#2]

Same for me this morning. Usually 4-5 Mbps on sync of 7500 ish.
0.5-2 Mbps varying. Just going to wait a while and see what happens before I start digging into whats wrong.
Rgds

[#3]

@scotty026
I've checked and can't see any obvious causes so I'd head here if that's still a problem: http://faults.plus.net
@outnabout2005
I've just updated the speed profile on your account as this was mismatched. Give it a go now and let us know if there's still a problem.

[#4]

Okay, not sure what that means Adam, but the speed is now back to normal. If that was down to whatever you did then many thanks. And thanks also for the speed of reply. Exceptional! 
Rgds
Colin

[#5]

Again speed tonight running slow was running at 8mb at 5/6pm now 1/1.5mb

[#6]

I think I have found the fault, if my SNR Margin(Downstream) is 4 or below my speed drops down to .5/1/1.5 mb no higher, is this normal ?