Thanks for looking.  I've included a few screenshots... one of the working toy example and one of the same code (i think  ) that does not work in a flat sequence in my larger program. The function of this VI is to open an .lvm file, process it, and display the important data.  Interestingly enough, I ran the program once with a bad .lvm file and the poperty node worked fine -- the graph read time [sec].  I am forced to conclude that somehow opening an .lvm file trumps redefining the property node, regardless of where the property node gets redefined.   
thanks 
Eamon