Setback for the effort to scuttle what has been a deadly insurrection.
Addis Ababa meeting opened with call for resolution of political, military crises.
Rights groups say oppression carried out under Meles has continued.
Calls for mass demonstrations to protest the arrests of 28 people on terror charges.
Comes after politicians in Cairo -- unware they were being taped -- suggested President Morsi attack or sabotage the project.
Continentwide organization helped liberate millions from colonial masters but has struggled to remain relevant.
Zenawi Meles' pictures and past statements have become commonplace throughout Addis Ababa.
Promised not to interfere in Congo internal affairs; also agreed not to support armed groups.
The meeting is expected to take place on Friday to try to move stalled agreements forward.
Nation has suffered many coups and rebellions since gaining independence in 1960.