1000 Genomes regenerated alignments for some of their datasets I seem to recall, therefore they have different names. If you go to the FTP directory in a browser, it is still there, but the file is not. I think you want this file : ftp://ftp.1000genomes.ebi.ac.uk/vol1/ftp/data/HG00154/alignment/HG00154.mapped.ILLUMINA.bwa.GBR.low_coverage.20111114.bam - Daniel Swan