Usually this happens if some device is disabled or removed that would cause your computer system ID to change. In my case, if I remove my USB wireless network transmitter, EZdrummer will ask to be authorized again. I simple correct the connection and try again and everything is fine.
Hope that helps you solve your situation.
Dave Modisette www.gatortraks.com www.plasticsamerica.com http://www.gatortraks.com/forum