I believe the issue with MC coexisting with WMC is caused by WMC. WMC does not detect which tuner is in use by another application, or on another computer. It relies on user configuration to decide which tuner is used on a particular computer. For example you need to designate tuner 1, 2 to computer 1, tuner 3 to computer 2, and the rest of the tuners to computer 3. If you did that, WMC on computer 1 will only access tuners 1 and 2. MC uses a more elegant solution. It uses any tuner that is not used by other applications. WMC on computer 1 will assume it can always access tuners 1 and 2, even if MC is using one or both of them. Any time two applications try to use the same tuner, bad things happen.