I've been getting this too, so I checked over on Sprint's forums. Someone suggested letting your battery drain completely, then recharging. They said that fixed it for them.
That sounds a lot like what a battery pull does, so I decided to try the simulated battery pull by holding the power button for 10 seconds instead. I just did it, so I can't say if it fixed the problem, but the notification is gone. Also, a problem I had with the weather widget just displaying "current location" instead of the name of the city I'm currently in appears to have been fixed, so at least the "battery pull" seems to have fixed something.