This happens with darcs 1.0.5 on a powerpc Mac OS X 10.4.4 system.
Just letting you know.
Michael
mpib:~/tmp michael$ darcs get http://common-lisp.net/project/cl-mathstats/darcs/cl-mathstats Copying patch 18 of 18... done! Applying patch 2 of 18... Unapplicable patch: Fri Oct 7 15:09:22 EDT 2005 Gary King gwking@metabang.com * meta.math and meta.statistics -> metabang.math and metabang.statistics
darcs failed: Error applying hunk to file ./dev/metabang.math.system