On Max/MSP 4.6.0, both Intel-Mac and PPC Mac, Mac OS 10.4.7,
(I've never tested it on 4.6.1)
I got "D A B" when I send "D B A" to "zl sort".
I got many similar results.
This could be a bug in zl.
(But I got "A B C" when I send "C B A" to the same object.)
It works fine on 4.5.7.
I'm sorry if it's already known.