Adnan wroteIf you live on a high floor and have an elevator with an inverter, it could be the cause.
Check if you get errors when the elevator is running.
I have issues with the elevator---I got a new TPlink modem a couple of days ago and I can see the SNR margin go below zero when the elevator runs (it mostly doesn't cut out like the old Technicolor that it replaced). Would replacing the old telephone wires with a shielded one help or are there other fixes? In any case, I am going to get a tech out here soon so he can check the connection at the telephone box downstairs and see if there is a difference.
Edit: here are my stats from this morning--no electricity and more importantly, no elevator
Mode: ADSL_re-adsl
Traffic Type: ATM
Status: Up
Link Power State: L0
Downstream Upstream
Line Coding(Trellis): On On
SNR Margin (0.1 dB): 106 107
Attenuation (0.1 dB): 465 253
Output Power (0.1 dBm): 184 106
Attainable Rate (Kbps): 2314 752
Path 0
Downstream Upstream
Rate (Kbps): 2047 751 0 0
Not great stats--it is a 2mb line from Ogero, and I am getting close to that now. When the elevator runs, the SNR number does turn negative and if it isn't for very long, my connection hangs on. If it is longer such as when natour goes to every floor to get pick up nightly garbage, then I lose the connection for a bit. Now, the technicolor modem which replaced this, would automatically lose the connection no matter what, so it is an improvement.