Debugging mirror selection

On my Fedora 17 system with yum-3.4.3-29.fc17, I sometimes see yum
choose a non-optimal mirror.  I have a mirror at my ISP, and Fedora's
mirrormanager is returning it (and only it) at pref 100 in the metalink
file.  If I trace urlgrabber, I can see it fetch some repodata files
from my mirror (without error), but then it starts pulling from another
mirror (the next pref in the metalink file).

For example, it'll pull repomd.xml and foo-primary.sqlite.bz2 from my
mirror, but then (for no apparent reason, no error logged) it'll fetch
foo-primary.sqlite.bz2 from another mirror.  If I fetch the files myself
and compare them, they are the same (so it isn't like it got a bad
download).  Sometimes it'll even go on down to the third server on the
list.

What can I do to fix this?

-- 
Chris Adams <[email protected]>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.