While running reprocessing we managed to stress out xrootd. We have an updated version of XROOTD from the developers 20080508. http://root.cern.ch/phpBB2/viewtopic.php?p=27678#27678
This version will be used along the reprocessing branch (Big Run GlastReleasev13r9). What we did to build this.. Starting from the source for v5.18.00b, replace the root/xrootd/src/*.tgz file, and update the Module.mk file to point to the correct version "20080508-0000". Then build, as usual. Unfortunately, this version of xrootd will not build on windows - it is hoped this version will make it into ROOT v5.20, and will be patched up accordingly. As it stands, we do not absolutely require this on the windows side - so Windows will use v5.18.00c.
The full source is available here: /afs/slac/g/glast/ground/GLAST_EXT/rh9_gcc32/ROOT/root_v5.18.00b-gl1.source.tgz