I've installed Back up to Dropbox on two other sites but on this third one I installed it and it does not let me select the Dropbox account. The settings page, under Dropbox Account Details, shows the Unlink Account button and "you have 0GB of 0GB (0%) free" but I never linked it! The Unlink Account button doesn't do anything either. How can I link this to my Dropbox account? I am using WordPress 3.5.1 and tried Backup to Dropbox 1.4.2, 1.4.3, 1.4.4 and now 1.4.5. Thanks.