No dialtone on FXS port but incoming works?

[dswartz]

So I finally got asterisk 1.4/zaptel installed and spent last night getting my polycom 320 working. I had the verizon landline plugged into the FXO port in channel 1 (rhino R8FXX-EC) and confirmed I could make outbound and inbound calls. Cool. I then moved the house rj-11 to the FXS port in channel 4. Configured an extension for it. Called that extension from the polycom - it rings, and picking it up works fine (audio both ways). Here's the bad part: if I pick up the cordless phone, I get no dialtone, and looking at an asterisk remote session, I don't see the expected message about Zap/4 being picked up. I know I have the 4-pin molex connector hooked up, and even if I wasn't sure of that, if it weren't, there wouldn't be ringing voltage. I'm assuming some zapata misconfiguration, but I used (IIRC) whatever genzaptelconf and ztcfg told me to. Any ideas?