Just remembered I needed to fettle the front mech on the InBred.
So went out, released the cable, adjusted the low limit screw in a bit then tried thightening up the bolt.
It got so far then just slipped. Bugger, thought it was just the bolt that had stripped threads (which I replaced last week).
So looked for a new bolt, all too long.
Try a bolt and washers to fettle it, first attempt had 4 washers and looked a mess.
I then found some of my M5 stainless bolts that are just slightly too long, fixed with 2 washers and all now working (looks like it is only the middle bit of the thread in the mech that is buggered, so the first bit and last bit grip ok).
Now all I need to do, just to be certain, is to find another 6603 front mech to replace that one (I don't fancy being stuck in the middle of France or Spain with no front shifting)