OK data library, (brand new). I upload one BAM file using galaxy's "Add Dataset" I start a new history, titling it, "testing multiple use". I import to current history. I run a job that reads the BAM file and produces some output. Everything works. I have 13 output data sets in the history, all showing green. Now I create a second history, called "2nd use same dataset same library" Again I check the box and click "import to current history" Then I try to run the same job as before... [bam_header_read] bgzf_check_EOF: Invalid argument [bam_header_read] invalid BAM binary header (this is not a BAM file). [main_samview] fail to read the header from "/.../galaxy/database/files/000/dataset_961.dat" (Ellipsis is mine, not Python's) Oh my, looking in that file space, I discover that my BAM file is at dataset_962.dat. Was gibt? Michael Moore .