I have found a possible defect in the gcrma 1.0.6 distribution. I noticed when I tried gcrma with fast=FALSE and got an error message that gcrma.bg.transformation not found, that the file gcrma.bg.transformation.R is missing from gcrma/R but this file is there in the gcrma 1.0.0 distribution. When I copied gcrma.bg.transformation.R from the 1.0.0 distribution to the 1.0.6 gcrma/R directory, then fast=FALSE works. Cheers, Dick ********************************************************************** ********* Richard P. Beyer, Ph.D. University of Washington Tel.:(206) 616 7378 Env. & Occ. Health Sci. , Box 354695 Fax: (206) 685 4696 4225 Roosevelt Way NE, # 100 Seattle, WA 98105-6099 http://depts.washington.edu/ceeh/ServiceCores/FC5/FC5.html