It appears that most of the problems are due to pilots not entering the data correctly, but that is only what we have heard in the interim. They are investigating the FMS boxes as well as the software. So I think it is too early to do a final WHY... The sids are fine as they are done up now, when the info is entered correctly and the box is working they nail it.
We have our standards here for RNAV, I would expect that they are compliant with ICAO, but since I am not ICAO conversant in RNAV, I wouldn't bet the farm on it... Got to run...
regards
Scott