I've been dealing with DSLX and VZ support since my last post, so I think we've reached a definite conclusion. I was referring to swapping the 327W for either option a) or b) above, whichever I could do for minimum cash. We've been up at full rated speeds for two days now, so I think the problem is solved. VZ sent techs to the house twice, and the second one was so good that he actually came inside and tested the inside line, both with his tester and connected to the two DSL modems I have, after verifying that the outside lines were good all the way back to the DSLAM. We made two changes: VZ swapped our connection to another circuit in the central office, and I'm using a Comtrend DSL modem that feeds a dedicated wireless router. The problem was still intermittent right up until we settled on this combination of changes, so we don't have enough information to be sure what was causing it, but I don't plan on using the 327W anymore. Maybe intermittent loss of sync with no other indications of problems is a sign that this modem is failing. I still haven't had that idea verified by anyone smarter than me, but it seems like it could be true in this case.