This presentation will discuss predictability and forecast issues associated with the Madden-Julian Oscillation (MJO) / Intraseasonal Oscillation (ISO). The analysis will be based on prediction and predictability experiments from a number of atmospheric general circulation models, including the NASA GLA, ECHAM5, and COLA AGCMs, as well as include discussion of the possible role that coupled sea surface temperatures (SST) may play in this problem. In regards to the latter, the discussion will highlight the problematic nature of so-called “perfect SST” forecast experiments in regards to the subseasonal time scale.