I went to run pythia within ROOT via TPythia6 (wrapped by EventSTructure pythia reader) taken from libPythia6.so ... it fialed. I checked STAR bugs and found that STAR bug-614 covers this problem. That report says it is a ROOT problem that is not backwards compatible and offers a solution of explicitly loading,

$OPTSTAR/alt/lib/libPythia6.so

I'll make changes to the estruct loading macros and test the results. If all goes well I will point the changes to Duncan so that these can be reconstructed via the estruct job-gui.