I purchased a HAI 81A00-2WHZB Zigbee Interface Module which worked OK until I attempted to update its firmware. The radio FW update went fine, but when I attempted to update the main FW, the ZigBee Updater said it was complete, but the display on the ZIM was blank, and it never returned. Luckily Amazon is great about returns, so I have a new one, but how do I prevent the same thing from happening again? Also, how do I know what has been fixed/changed in each update?