Expresso not working on my win 7 machine, Coffee works fine

Expresso doesn't pick up my double clicks on My Win 7 Prof 64-bit SP1 machine. Coffee (http://www.lupopensuite.com/db/coffee.htm) seems to work fine.

From browsing the forums, I understand there's some issue involving the makers of Coffee not properly attributing work. Would far prefer to use Expresso. Any ideas what might be going on?