Any joy on the C5 issue? I have the same problem with a 565 and a 506. The 565 is set to controller, but they both show as controller when clear is pressed. I've checked the wiring with a multi meter according to the C5 wiring diagram and it looks correct to me.

The 565 is also connected to a pair of DSP5000s - I've just disconnected this M5 cable and I get the same result

-- Paul --