Hi
There were no obivous errors in the logs of any of the hosts. But after some more digging on/in the SCCM side I came across this post you were part of http://communities.quest.com/thread/16794?tstart=30 which pointed me in the right direction with SCCM itself not processing the "MOF" file generated by QMX.
The listed fix in the post didn't itself work for me but after looking in the "Component Status" logs for the "SMS_MP_CONTROL_MANAGER" on the effected SCCM sites there were errors pointing to the SMS_DEF.MOF files still after trying the steps. So I just copied the "SMS_DEF.MOF" file from our Central SCCM server and over wrote the file on the "broken" servers" after which I re-ran the "Start All" in the QMX console for all the Platforms we have clients in then everything came good.
Cheers
Karl