MessageCountEvent has null messages in it

[jchang]

I have a MessageCountListener implementation, and when messagesRemoved(javax.mail.event.MessageCountEvent messageCountEvent) is called, sometimes everything is fine on the event object, but sometimes:
1) I get an array of null messages.  getMessages() returns an array of one, and it is null.  Or...
2) I cannot get the UID for the message.  I can get the parent folder, but when I call parentFolder.getUIDValidity I can't get it.