Keyboard viewer appears during Fast User Switching in Mac OS X 10.7

Apple Article TS3104 addresses Keyboard Viewer appearing during Fast User Switching in Mac OS X 10.6. I am running OS X 10.7, Lion, and have the same problem: when logging into a different account, Keyboard Viewer appears several seconds after the Password dialog box appears. However, the solution posted for 10.6 does not work: clicking Hide Keyboard Viewer during Fast User Switching dismisses the password dialog box and then does close the Keyboard Viewer, but the problem recurs the next time an attempt is made to switch users. Any ideas?