I installed the plug-in set the settings and then selected to do my first backup. It failed with the following message:
19:25:10 : A fatal error occured: Directory name must not be empty.
19:25:10 : Backing up WordPress path at (D:\Websites\WordPress MySite.com/).
19:24:55 : Backup started on Monday November 19, 2012.
I wonder if the space in my site path is causing the issue?