Did you ever find an answer to this problem? I just posted a topic with the same question.
The JDK 1.4.2 has a regression in class loading behavior that does not correctly load the array class references. See the following bug on sun:
Ouch, I wish I had seen your post a few hours ago :)
See the following link for a hack workaround and a full explanation.
BTW, we've been told that JBoss 3.2.3 correctly accounts for the Sun regression, and will load the class correctly. This is explained in the above link as well.