After the latest update to the yum-2.5.1-3 from FC5 devel tree, yum eats alll available memory and does not work even "yum clean all" has been run. This may be related to the unresolved dependency problem with libneon but older version of yum works even this.
Thank you for the bug report. This particular bug has already been reported into our bug tracking system, but please feel free to report any further bugs you find. *** This bug has been marked as a duplicate of 179547 ***