Thanks Carl, I have been using MConfig & I've been "stamping" my files too - but it's a good tip to remind people of.
The problem that I encountered is that when I re-typed, MConfig didn't carry my old config over - in fact it decided on what sources I had itself (based on the connections I had) which were totally wrong !

I'll give it another go just to check in case I was doing something wrong, otherwise I'll just start from scratch with type 1 - shouldn't take too long - but I'll have to re-run the MRC measurement routine.

I should have time later - I was nuts enough to watch the F1 live - but don't worry, I wasn't nuts enough to watch the delayed qualifying !