Looks like there is a low-probabiltiy deadlock somewhere in the Finalization code.
http://jikesrvm.anu.edu.au/cattrack/results/rvmx86lnx32b.anu.edu.au/commit/4754/prototype/default/SPECjbb2000/SPECjbb2000/default/Output.txt
Fixed in r14878.
Fixed in r14878.