Try to connect your controlled gear directly to the device that is controlling it. If you have an AV receiver with an RS232 port, connect it directly to the RS232 port on the Media Director instead of using an RS232-to-USB adapter. If you have a home automation controller with a USB plug, connect it directly to the core's USB port instead of a USB hub. Hubs and adapters can have issues with the power management side of the USB spec. This can cause devices to simply drop off without warning, and not notify the kernel that they were dropped off. This can cause LinuxMCE to reassign a new device ID, which trips up the plug-and-play (PnP) code.