There was a problem with the converter wherein only the last cluster got written to the Root file - Ncluster times! *This only affects the fastMC.* I have fixed the SLAC version (asc2root.cxx). Cluster behaviour in the fastMC looks fine now. The fix will be in the next distribution with the revised Event classes. Richard -- Richard Dubois SLD, Stanford Linear Accelerator Center [log in to unmask] http://www.slac.stanford.edu/~richard/ 650-926-3824 650-926-2923 (FAX)