[CentOS] Yum update worrisomeness

I went to do an update a bit ago (10:30 or 10:45 EST), and first, it got to
rhel-i386-server-5/filelists                 |  14 MB     02:23
and was running at 2Kb/sec to 4Kb/sec, then, when I killed it and
restarted it about 20 min later, it went at about 28Kb/sec, then died,
reporting:

Error: failed to retrieve repodata/filelists.xml.gz from rhel-i386-server-5
error was [Errno -1] Metadata file does not match checksum

This makes me *very* nervous. Anyone know anything?

      mark