MCabZ, I owe you a beer.
You were right. In error 1909s on program installs, the Program Data directory is set with Read-Only attributes. When the install fails and you get the 1909 error, stop. DO NOT CLOSE the install or click any button. Simply open up another window, browse to the Program Data directory (C:\Program Data\whatever-the-name-of-the-directory-is, like C:\Program Data\Apple for an iTunes install), right click and select properties, clear the Read-Only attributes at the bottom of the box and Apply. Then return to the failed install and click retry. TADA! Your install will succeed.
My only problem is that I don't know how to keep this from happening every time.
Anyways, public props to you. Thanks,