Thanks guys for your responses, I had tried going into angle editor and setting the dual mono there, but unless I have missed something you cannot edit in the angle editor, no blade in the angle viewer! so when you go back the the multicam clip in the in the timeline the two channels are are still locked together.
However taking your advice looked at FCP preferences I noted that under the import tab, the box "separate mono and group stereo audio" was ticked, unticked it, cleared project, imported footage yet again, waited as usual for import/transcoding to finish, made sure both clips where dual mono, made new MC clip, dragged into timeline and its all there, two clips with dual mono! thanks.
Not sure what above preference actually does as the highlight doesn't explain it fully, as FCP help menu is good at the sales and not at real issues.
FCP has really locked up since the last update, yesterday part of trying to solve the above, I tried to "synchronise" the two clips instead of MC and it just gave me the spinning Katherine wheel for over an hour, tried to cancel, tried to quit FCP, tried to close MAC, couldn't force quit for over an hour, other software was working, had to pull the plug, not the first time when clicking to do some action in FCP you get the spinning wheel for long time and have to force quit, other software haven't had a problem, I suspect bugs in latest update.
Anyway thanks again for your responses, all said the same thing which is comforting, will see how in goes.
Still learning the new layout since the update last autumn,
Thanks again from the UK
Howard