i have a problem with that exception, actually, when i click on the `calloutAccessoryControlTapped` button of the pin i got this exception, i try to track the error by the `NSLog` in the console and i found the only pin which caused this exception have the value `<null>`, i explain by some code :

```
for (int i=0; i<[array count]; i++) {
           NSDictionary *stationEnCours=[array objectAtIndex:i];
           location2D = (CLLocationCoordinate2D){ .latitude = lat, .longitude = lng };
           MyLocation *annotation=[[[MyLocation alloc]initWithName:ensStation distanceVersLaStation:distance coordinate:location2D]autorelease];

//here we set the properties before we get call to addAnnotation annotation.stationAdress=[stationEnCours objectForKey:@"ssiphone_adresse"];
           NSLog(@"%@",annotation.stationAdress);
           [mapView addAnnotation:annotation];
}

```

i have 4 stations, in the console i got this :

```
2011-05-11 22:27:11.768 TopStation[2370:207] A 51 - Aire de la Champouse
2011-05-11 22:27:11.769 TopStation[2370:207] <null>
2011-05-11 22:27:11.769 TopStation[2370:207] 467 Avenue Henri Mauriat
2011-05-11 22:27:11.769 TopStation[2370:207] Route de Berre - Jas de Bouffan

```

the second one is which cause problem later when i try to click on its `calloutAccessoryControlTapped` so i checked my database and its adress is a `string` and it's not `null`.
i am little confused, why that exception although all is retrieved as `String` ?? i have also tried to do the same work but on the server side and all is ok, it's not displaying me `NULL`, only in the iPhone side and for this station.
If this help, the adress of the station which make problem is :
**1 Boulevard du Maréchal Juin**