Not yet; this is something with changes done by Apple.
I know Juniper is working with Apple on this; however, I do not have insight to provide further.
So I finally got around to doing some more testing on this. I set up another realm on my IVE (7.1R4) and enabled Host Checker on it. I was able to duplicate the same crashing problem if I logged in using the Network Connect client directly after I upgraded to Java 1.6.0_31. Then, however, I applied the latest update that just came out a week or so ago (1.6.0_33), and now the problem appears to have been fixed. Can anyone duplicate/confirm?
Confirmed, this is expected by Juniper, from Apple, to be resolved in 1.6.0_33.
I have seen it resolved in several cases outside Juniper-based testing.