Two identical machines, both running CentOS 4.3 plus all the errata. First one: yum update went for a while and hung. At the bottom of the yum.log file was this: Aug 31 06:58:01 Updated: control-center.i386 1:2.8.0-12.rhel4.5 Aug 31 06:58:09 Updated: iiimf-le-unit.i386 1:12.1-13.EL.5 Aug The python process was in the process list, but it was consuming no CPU time. I let it go for a couple of hours, then killed it and played with the duplicate removal script posted previously. Second one: I tried a combination of suggestions previously posted: yum clean all yum update yum sqlite python-sqlite python-urlgrabber python-elementtree yum clean all yum upgrade This also ran for a while and then hung in a similar fashion. The tail of the yum.log is: Aug 31 11:29:08 Updated: at.i386 3.1.8-80_EL4 Aug 31 11:29:09 Updated: samba-client.i386 3.0.10-1.4E.9 Aug 31 11:29:21 Updated: anaconda.i386 10.1.1.46-1.cento Suggestions for future tries on other machines? Thanks much, Zube