This might be related....
In ROOT 2.20/06 on DEC Alpha Unix (CXX v.6), when using the DEC
eXcursion (Version 3.0.554) remote X-Server, the following 4 lines
cause a "disconnect":
Root> TNtuple *N = new TNtuple("N","Test Ntuple", "x:y");
Root> for(int i=0;i<10;i++) N->Fill(i,i);
Root> N->Draw("x:y>>h1"); //Draws correctly
Root> N->Draw("x:y>>h2"); //Does not draw
Root> h1.Print();
//Look at the Histos
TH1.Print Name= h1, Total sum= 10
Root> h2.Print();
TH1.Print Name= h2, Total sum= 0
It does not happen with the other X-Server I tested (X-Win32) and it
does not happen when using VNC.
-Scott