Geoff,

>Cant say that I've had to much of a problem with cursors.
>
>In this instance, however, it is not the RowSource that is at issue but the ControlSource. I suspect it is something to do with the underlying type of properties in an object or defined by using Public,Private, ...

I don't ever bind controls to public/private memvars it's anti-OO *g*

I don't have problems when binding to form/object properties or cursor/table/view columns. You should make sure that your property is is of the correct type and value range before you attach the cbo to it.