iphone - how do I detect location service disable for my app?

IOS4 has recently introduced the possibility to enable/disable location services for a specific application.

I need to detect if this settings is enabled/disabled for MY application.

First I have tried with:

if ([CLLocationManager locationServicesEnabled])
    {
       ....
    } 

however this refers to the global location service and not to the specific application setting.

Second I have tried to use

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
   ...
} 

It works but it gets called both in case of service app setting disabled and in other cases like, for example, if a measure fails for some reasons.

I need a code to detect if MY application is allowed to use location services.

How can i achieve this?

Thanks for your support