My master bus is bypass in automatic

Hi!, Im using cubase 6 and in the master bus Im using the british MCL-2269 nomad factory plugin, but I dont know why, after few minutes the channel (master) is bypassed!!, and sometimes the plugin too. Could you tellme how can I solve this problem please?. If I activate again the channel, could be working fine again for a few hours but sooner or later is bypassed again, and I dont know when, then I need to check every 10 minutes aprox.

My best regards