I think the bug might be fairly subttle in so far as I couldn't
reproduce it between hosts on my local network.  However, given a large
number of foreign addresses, the problem seems to come up right away.  So,
I wonder if it's something like a variable not being cleared every time a
new packet comes in or something like that.  Also, if it helps, once a bad
address is found, that address seems to consistently not work.
-Brian