Once a site has been moved from the "Favorite Sites" column to the "Active Sites" column, it can't be moved back to the "Favorite Sites" column using only the keyboard when it is in the top position of the "Active Sites" column. The keyboard interaction bugs effectively make it unusable for keyboard only users on the "Customize Tabs" page of the "My Workspace: Preferences" tool.
Here is a brief (1 minute) video of the issue:
I'm guessing the problem is because of the locked "My Workspace" entry in the "Favorite Sites" column is locked into position preventing the normal insertion of a site in first position of the "Active Sites" column's attempt to move into the "Favorite Sites" column.
The issue is 99% solved. However, there is no visual indication of focus when using the keyboard to navigate between sites in IE 9. In Firefox a dark black outline signifies the active site.
provide visual indication of focus for active site in IE, similar to Firefox.