FCPX MacBook Touch-Bar Trim Tools Greyed Out

Using 10.6.6 - my last project (using this same version of FCPX) allowed me to use the touchpad trim controls but they are greyed out for my current project. I haven't changed versions of FCPX.

A real pain - is anyone else having this issue and, more importantly, does anyone have a fix?

The attached pic isn't that clear but take it from me, they are greyed out.

Thanks.