Desktop 3.0 with Leopard Can't Share USB Drive

Good morning,
I am running Desktop 3.0 5582 on a Leopard Macbook Pro.
While the VM is not running and I go into config. to add an external USB drive as a shared folder (have done this in previous versions no problem) when I click on 'add folder' the Mac OS file finder window opens but is not clickable. Mousing over it has no effect and it can't even be closed until I close the Parallels config. window.

Any thoughts most appreciated.


J