ghettomaster: HI Quaywe,
You still haven't posted the modem stats as requested several times. These are not the logs - they should show things like line speed, attenuation, etc. You also haven't tried a new modem.
The fact of the matter is it's either the modem or the wiring, and a temporary modem would let you know either way. You say you don't have any friends with VDSL that want to go without internet for a couple of days, and fair enough, but what if you asked one of your friends to swap for a few days. This way if they start getting problems and you don't, you can be even more sure it is the modem. If they have concerns, promise them you'll swap back as soon as they get problems if they do.
GM
I've sent an email around at work so am waiting to hear if anyone can help me. Better than me having to chase my workmates though I would have thought a good idea would be for Slingshot to just carry a few known good spares to help eliminate the modem as the problem. Surely that would save everyone involved a lot of time and money trying to figure out whether it was the line or the modem causing the fault?