Cleaned OverlayMediator. Moved strings to /res/values/strings.xml Solved the bug with disappearing OverlayItems. The actual reason was the caching of OverlayMediator object. The instance variable “activity” was the old one, and the getOverlays from the activity’s lusitesMap were old. So it couldn’t work. The solution is to force OverlayMediator to renew its instance variable LUSitesActivity activity each time the static method getInstance is called: public static OverlayMediator getInstance(Context context) { if (singleton == null) { singleton = new OverlayMediator(); } singleton.