there actually is a .cpkt in *every* directory - its just not visible

no - its not just hidden and its not possible to un-hide it

just tell you Unix guys to take a leap of faith and try a "cd .ckpt" :-)

you can also try creating a symbolic link like "ln -s .ckpt checkpoints" if thats easier for them

Thanks guys. I'll see if they 'like' this answer.

It's funny, I seem to forget the simple solutions but remember the complex ones.  :-)

Jim