I am not aware of any changes in this regard.
Eric, is anyone in the ACR team working on this? It was acknowledged on the feedback site, and Steve G was involved with the forum discussion and was trying to get it looked at, but this was never confirmed.
The problem did turn out to be two similar problems, one of which was fixed in ACR 8.2.
The other problem continues, and is triggered by a combination of Lens Profile Corrections and some unknown condition. I guess it could be a Bridge bug, but it definitely appeared with ACR 7.3.
On Bridge forum: http://forums.adobe.com/message/4927315#4927315
On Camera Raw forum: http://forums.adobe.com/thread/1236721