No worries. Thanks Robert!
As long as it's doing what it's supposed to and I'm not being too dumb to drive it I'm happy!
I'm just used to having that feature available to me in registax, so I was wondering why I couldn't get it to work...
I'm just learning K3CCDTools for processing more out of interest than anything, but I have to say I'm impressed with the 2x image enlargement feature in K3. It seems to do a smoother job than the equivalent routine in Registax... but perhaps that depends on what settings you apply in registax - I haven't exhaustively explored them all!
Al.