Random Corruption of Player Prefs on Suspend?

Hi,

I've gotten reports from a player of player prefs being deleted completely when my game goes to the background on iOS devices. It happens very rarely ... I've never managed to replicate it myself. Has anyone run into something like this? If so, is there any best practice solution? Should I try to call PlayerPrefs.Save() or something when the game gets pushed to the background?

thanks,