Hi: I would like some suggestion on how to go around the following error with simpleaffy: Using: R 1.9.0 simpleaffy 1.2.3 Code: rawdata <- read.affy(covdesc="covdesc.txt") rma <- rma(rawdata) pw.ua <- pairwise.comparison(x=rma, group="treatment", members=c("u", " a")) Error in get.fold.change.and.t.test(x, group, members, logged = logged, : a or b too big or not enough iterations in betacf I got this error initially with a lower version (1.09) of simpleaffy, and then upgrade it to 1.2.3, as suggested in one of the archived email. But the error did not go away. Any suggestions would be much appreciated! Jan Folia