The board behaves in a current iMac and MacBook Pro in any format status (the plate was 2 x changed and differently in the test format) identical startup and shutdown. The board delayed the shutdown over minutes, the system (current Mavericks) then travels down but clean. Unlike at boot: The plate prevents the registration process and flashes. Only when removed (USB 3.0 ports repeatedly exchanged) immediately appears the login window. Only after logging in and reconnecting the SSD this is detected clean. Daily plugging and unplugging is troublesome.
The manufacturer was contacted, but has so far not provide a solution. The workaround: USB 3.0 Hub bought for around 20 EUR and infected disk there. Runs there properly, because it is consistently supplied with power from the hub (there is at the hub an on / off), just after the shutdown.