Thanks very much for your replies.
Can you (anyone) confirm that you have, say, The Andy Griffith Show or I Love Lucy offered for recording on ME-TV on March 1 or later? I have nothing available on any ME-TV series after February 28. On one local guide service ME-TV is listed simply as "paid programming" from March 1, but on all other online TV listing services there is accurate program and episode information. So it may be an issue of when ME-TV shared this information with guide providers and when/how often Tablo's own guide service reboots its database.
The Ant-TV episodes have now propagated through on my schedule (as on other on-line TV guides), so I guess when they change seasonal schedules (as they are doing from March 6) they don't send the episode information out until close to the changeover date. They only put it on their own website in the last 48 hours, although the changed schedule with generic series names has been available for much longer.
I did open a ticket (with zip code, etc.) but as far as I can tell Tablo haven't yet contacted the guide service, but I hope and trust they will. (They only asked me to put my device in heartbeat mode but said nothing about the program guide.)
Thanks again for your responses. Much appreciated.