New to FTTC - >50% speed drop since yesterday

[#1]

My FTTC got connected yesterday everything was fine - ~72mb/s down and ~19 up when using speedtest.net. Today thats gone down to 40 own and 6 up.
The member centre is saying that my line is connected at 77.4 but because BT have given me a crappy locked down ECI modem I have no way of actually checking the sync speed.
Plusnet support - can you check my line speed and maybe give it a kick. My only guess would be that DLM saw me change from the plusnet router to my wrt-based router and throttled things back.

[#2]

Interesting .....
Main Fault Location OK
Sync Status In Sync
Downstream Speed 70.4 Mbps
Upstream Speed 20.0 Mbps
Appointment Required N

Everything appears to be OK on our side as you've seen via the portal. If you could ensure you've tried wired and provide some speed tests on this would be handy. Thanks.

[#3]

I did notice that my ppp session restarted and improved last night, shortly after posting. I assumed someone from plusnet was working on it.
I'll check what its like when i get home this evening. For what its worth i did the speed tests using a wired connection.

[#4]

I didn't see anyone making changes earlier. Let us know if you've still got problems tonight though so we can look further into it.

[#5]

Its better today but still not back to where it was..
http://www.speedtest.net/my-result/4257894174
Any way to reset the dlm on the line to get it to resync back at the full speed? I think my changing of the router has caused problems

[#6]

Is it not the case that FTTC still has a training period ? or was that just for early installs ?

[#7]

There is no training period on fibre the line is in a fully open state for 48hrs ie it will be at the fastest it can go, after 48hrs DLM starts and will make any changes that it feels it needs to based on how the line has been behaving in the 48hr period.