Well I tried the idea I described above, placing a 2Wire filter at the NID and wiring the modem to the straight line (DSL) while connecting the stations to the output of the filter. Admittedly, I don't have a DSL tester, per se, other than my Harris "data-safe" butt set which starting beeping when I went across the station side. Also, I could hear faintly the modem sync up even while monitoring the station side...I shouldn't be hearing that if the DSL signal has been separated. Seems this idea should work. I replaced the 2Wire with a Keptel splitter (which looks like it works the same way: it outputs voice only), and the Keptel always works. I'm stumped why this 2Wire thing doesn't work.