Hi everybody, I know that this has been reported before but I haven't seen any solution. I have been consistently getting segmentation faults whenever I use justRMA with a cdf environment other than the standard affy cdf environments (for instance hgu133). I have tried using my own alt cdf environments and Laurent Gautiers' altcdfenvs at "http://www.cbs.dtu.dk/staff/laurent/download/maprefseq/" Everything goes fine until the calculation of expression. I have tried with both destructive = TRUE and destructive = FALSE (rma_c_complete vs. rma_c_complete_copy), the fault persists. When I use the default affy environment it works fine. > exprs <-.Call("rma_c_complete",probeintensities$pm,probeintensities$pm,probe names,ngenes,body(bg.dens),new.env(),normalize,background,bgversion, + PACKAGE="affy") Background correcting Normalizing Calculating Expression Segmentation fault Did anyone experience such a thing? I am using R 2.0, and the latest version of affy. thanks.