Apparently this is a "universal" problem with NAD's latest genration of receivers and processors (ie. T775, T785, T175, etc.,..) you may want to follow the other respective threads:
http://www.avsforum.com/avs-vb/showthread.php?t=902321
http://www.avsforum.com/avs-vb/showthread.php?t=952677
http://www.avsforum.com/avs-vb/showthread.php?t=902321
http://www.avsforum.com/avs-vb/showthread.php?t=952677