Right-click the file, from the properties dialog on the "General" tab there should be an "Unblock" button at the bottom right (at least on Vista there is).
Hope this helps...
Interesting. My Vista Business install does not have the 'unblock' option.
However, on a security related hunch I copied the file to my local desktop (as opposed to running from a network share in the domain) and lo and behold, it worked!
Sometimes it's true, as Wayne Dyer is quoted: “If you change the way you look at things, the things you look at change.”
Hopefully manfromky's post will help others, if not, then I hope mine does.
Thank you manfromky!