BackWPup Won't Save Settings

Upon clicking the “Save changes” button, I get a blank screen. This is the URL that appears:

http://example.com/wp-admin/admin-post.php?action=backwpup

If I then visit that URL in my browser, I get a WordPress message:

“Cheating, huh?”

I have to manually type, “http://example.com/wp-admin” in my browser to go back to the WP admin. Upon navigating to the BackWPup interface, my settings are Not saved.

Any ideas? Is there a place I could edit something in my database?

http://wordpress.org/plugins/backwpup/