Enable and disable a Broadcast Receiver

Well, what you basically have seems OK. I have the following code in one of my projects:

boolean enabled=prefs.getBoolean(key, false);
int flag=(enabled ?
            PackageManager.COMPONENT_ENABLED_STATE_ENABLED :
            PackageManager.COMPONENT_ENABLED_STATE_DISABLED);
ComponentName component=new ComponentName(EditPreferences.this, OnBootReceiver.class);

getPackageManager()
    .setComponentEnabledSetting(component, flag,
                                PackageManager.DONT_KILL_APP);

I use this to disable a BOOT_COMPLETED receiver when I don’t have any active alarms that need to be scheduled.

My guess is that your ComponentName is not set up properly (e.g., your leading .). Try the constructor that I am using, that takes a Context and a Class as parameters.