I tracked this back to before the split of 'abcl' from 'j' observing the error through [rev0 of the copy of abcl][1] I keep in Mercurial], so can confirm the lack of regression back to 2008-12-20.
0 e7def953d497 2008-12-20 20:35 +0100 ehuelsmann [svn r11457] Create separate project directories for ABCL and J.
[1]: http://trac.common-lisp.net/armedbear/changeset/11457/trunk/abcl