The following changes are madeto fix the histogram problem
1> geantBranch -> geant
2> delete: //Efficiency   if (gRandom->Uniform(1.0) > eff){cout<<"REMOVED"<<endl; continue; }
3> mBookHisto=kFALSE; -> kTRUE

The following link is the changes I have made to move to a real vpdSimMaker (by deleting Tof related stuff).
http://drupal.star.bnl.gov/STAR/blog/kxin/2010/feb/09/vpd-simaulation-maker

The resulting root files look OK (/star/u/kxin/VpdSimProj), with plots available, but maybe it needs further tests.
Questions:
While running the bfc.C, I got several warnings: Wire Plane is empty
Does the parameter "y2008a" need to be changed?