Just tried the comms cable before I read your reply and it work in the HDMI video mode, my dealer was told by M that I should not use it my set up as the control was via HDMI. Strange that the 421 did not require a comms cable to work. I have a G98 and a G68, the HD621 indicates that the comms should go to the G98, is this correct?

Thanks, will try the last valid option.

David

861v6 ID41, HD621, G98, MC200, DSP7200, DSP7200HC, DSP5500 (rears), D2500; Oppo BDP83, PS3,
- Other rooms 3100, F80