It's a bug which has been known for a LONG time (I think all the way back to C1). The latest manifestation of it is a little different. Obviously whatever memory clobbering is going on is now changed due to the latest 64 bit compile. So the most recent experience I've had with it is putting it into the mixing channel, hitting the grayscale button and then you're messed up. The button partially disappears and you can't switch it back. Other manifestations of it have been issues with he pattern of the wires not rendering correctly. I used wires in the pool edge for my render of all the smily faces swimming in the big pool and it never really worked correctly. In addition, other users have emailed me about it with similar problems. According to some, it's been reported at Daz but I haven't personally checked.

-Kix