Ok, thank you. So the problem with the original itinenary (JNB-MRU-LHR-ARN-LHR-DFW-HNL-NRT-HKG-AKL-SYD-LHR-CDG-LHR-NBO) is that the tail -LHR-CDG-LHR-NBO is possible only with just transits in Europe.

Mileage Monkey didn't make a difference between stopovers and transits so I was puzzled if one can really do the EUR stopovers in two parts..

Yes, this was a xONE5. I was just puzzled how much one could put to the EUR at both the beginning and the end. Even something like JNB-MRU-LHR-ARN,HEL-LHR-LAX-NRT-HKG-SYD-LHR-CAI,DXB-LHR-NBO was valid by MileageMonkey. I wonder if that'd be bookable, though..