Welcome to the XCMS user forum - please read before posting! June 09, 2011, 12:36:26 PM If you report bugs, please include as many details as possible:the R and XCMS version you are using, i.e. the output of sessionInfo()the steps to reproduce the problemif an R function errors out, the exact place of the error can be shown by typingtraceback()Ten Simple Rules for Getting Help from Online Scientific CommunitiesPlease use the search function to browse this forum for possible answers to your question.In addition to that, an archive of the obsolete xcms mailing list is available.Ralf.