Hi Cece,
Firstly, leave your router powered up 24/7 for the time being, don't do any resync's, let's see if that 3776 sync rate can be maintained
Does
https://portal.plus.net/my.html?action=data_transfer_speed still show your profile as 3000? If it doesn't, and doesn't by tomorrow, we'll need to get someone from PN to give it a kick (assuming you haven't synced at below 3424 in the meantime!).
As you haven't got any extension wiring/sockets, unless you are technically minded, I wouldn't worry about the bell wire, but FYI if you look at the back of the detached faceplate you should see some IDC terminals numbered 2,3,4,5. In a broadband scenario only terminals 2 & 5 should be wired up for extensions. If you are technically minded and would like some further information, I could post you a few links.
You haven't said whether you are using wireless or ethernet. If wireless, low signal or interference will affect your throughput. Try running
http://www.mybroadbandspeed.co.uk/ to see what results that is giving (forget BT speedtester at the moment, we've got all the information that can provide at the moment).
If you are using wireless, 2 things - a make sure you're using the highest security encryption and have set a passphrase - not a straight word - put a number or 2 in it and if you've not got a good signal try changing channel.
For the purpose of testing, best to connect using an ethernet cable, if it's inconvenient to move the computer to the router, get a suitable length of ethernet cable (cat5e or higher standard - complete with plugs either end of course). When set up (also if not using the wireless) turn the wireless off so that no-one can hack in.
The other thing that can affect throughput (bearing in mind your profile is correct and consistent with the sync speed) is exchange and network congestion/problems. Check your exchange VP status using
http://usertools.plus.net/exchanges/With regard you latest stats/plots, first thing Did you/have you got RouterStats running as well, if so can you post the Noise Margin graph that covers the time 1105 -1115.
Secondly, on the DMT plot, unfortunately there is quite a nasty spike there at about 1112, it was sufficiently severe to change the scale of the plot to 0,40,80 (normally 0,5,10). That scale will also make the rest of the graph look flat! This could be due to an intermittent line connection, or possibly far less likely the router was busy.
It may be an idea to leave a corded phone plugged into the filter for the time being, then if you spot any anomalies on the noise graphs, you can have a listen to the line. So that this may help in the future, who do you pay for your phone line rental?
FEC errors show that error correction is taking place, but too many will slow throughput, but I don't believe yours are high enough to be the cause of the current low throughput.
There is the possibility you may be in a rather noisy environment from a Radio Frequency Interference (RFI) point of view, can you briefly describe whether you are in an urban or rural area and if there is any (semi-) industrial things nearby. Don't give away any personal or location information.
