A couple of days ago I started getting a notification for a voicemail message that doesn't exist. The notification only shows up right after I start up the phone. Shut down the phone, swap batteries, there it is. Do a restart, there it is. I've gone through all the settings and didn't find anything that might clear a cache if there's a notification that won't delete otherwise. I even tried leaving myself a voicemail from my home phone, then listening to it and deleting it. That worked for everything but the ghost voicemail notification. Any suggestions?