Thanks, drewk.
When you say across the line, are you bridging both legs? Where, exactly, are you installing the resistor?
I have the same fluctuation and I wonder if this is the final push that's gets me onto fastpath
Each leg of the resistor is connected to one of the two wires of the ADSL phone line: one leg to the "tip" wire and the other to the "ring" wire as they are called (red and green in my case).
Actually, I placed the resistor on a terminal strip and wired that into an unused RJ11 phone jack that I had laying around: one end of the resistor goes to the red wire, the other to the green. (Which wires you use depends on your particular telephone line wiring). Then I just use a short length RJ11 phone cord to connect it to any vacant wall jack: plug one end of the cord into the resistor jack and the other end into a wall jack that carries the adsl/phone line.
See the photo; yellow and black are not used in my phone system. Red and green are the live wires: there is approx 50 volts across them; more when the phone rings, so you would want to make sure none of the terminals is exposed to touch before plugging it in.