Modem users remember.... If you don't have POTS (Plain Old Telephone Service) but use a VoIP phone service (cable phone service is VoIP) expect a lot of trouble connecting to modem lines. If you make a long distance call, that may use VoIP too w/o your knowledge. Such connectivity will be very hit and miss and seemingly random.
I'm not saying ReplayTV/Earthlink don't have lots of issues, just that many folks have changed home phone services and not realized their end could be part of the problem.
I know it's happening because I hear folks call into the Perc/Laho dialup line to set the clock, get IR codes, etc. I have the speaker turned on and I can hear sync problems when folks are on a VoIP connection. Sometimes it works, sometimes it doesn't. But the computer tries.

Personally, I use an Ooma for my home phone. When I was on DSL, my RepalyTV 3000 seldom had connection problem to Replay or Laho. I switched to cable internet and now can't connect. I tried everything I could think of to make it work, but it just doesn't work. Luckily, I don't need it.
Robert
Edited by Reden - 9/22/12 at 9:40pm