For my VAIO, this resolved the issue. There may be something similar for the Event Service that you might be able to locate.
Start > Control Panel > Administrative Tools > Services
Locate the
VAIO Event Service and right click > Properties
Change Startup Type to Automatic and Start the Service
(to turn on the on screen display)
Change Startup Type to Disabled and Stop the Service
(to turn off the on screen display)
Hope this helps