UIMapView shows wrong region sometimes - iphone

Question

When I show UIViewController with UIMapView, in viewDidLoad I add PointAnnotation to map and to array. Then I calculate the region for these annotations and set that region to map.
The point is that sometimes (basically only once after installing app for the first time) the map shows region for equator even if my data is correct.
-(void)viewDidLoad
{
NSLog(#"Spot: %#", _spot);
_annotations = [[NSMutableArray alloc] init];
[super viewDidLoad];
// Adding annotation of spot
CLLocationCoordinate2D annotationCoord;
annotationCoord.latitude = self.spot.latitude;
annotationCoord.longitude = self.spot.longitude;
POPointAnnotation *annotationPoint = [[POPointAnnotation alloc] init];
annotationPoint.coordinate = annotationCoord;
annotationPoint.title = self.spot.name;
annotationPoint.subtitle = self.spot.address;
annotationPoint.type = PointAnnotaitonTypeSpot;
[_annotations addObject:annotationPoint];
[((SpotsMapView *)self.view).mapView addAnnotation:annotationPoint];
[annotationPoint release];
// Adding annotation of user position
CLLocationCoordinate2D userCoord;
userCoord = [[POLocationManager sharedInstance] location].coordinate;
POPointAnnotation *userPoint = [[POPointAnnotation alloc] init];
userPoint.coordinate = userCoord;
userPoint.title = NSLocalizedString(#"Punkt startowy", #"Punkt startowy");
userPoint.type = PointAnnotationTypeStart;
[_annotations addObject:userPoint];
[((SpotsMapView *)self.view).mapView addAnnotation:userPoint];
[userPoint release];
[((SpotsMapView *)self.view).mapView setRegion:[self regionFromLocations] animated:YES];
[((SpotsMapView *)self.view).mapView setShowsUserLocation:YES];
}
and region here:
- (MKCoordinateRegion)regionFromLocations {
CLLocationCoordinate2D upper = [[self.annotations objectAtIndex:1] coordinate];
CLLocationCoordinate2D lower = [[self.annotations objectAtIndex:1] coordinate];
NSLog(#"Loc Upper: %f, %f", upper.latitude, upper.longitude);
NSLog(#"Loc Lower: %f, %f", lower.latitude, lower.longitude);
// FIND LIMITS
for(MKPointAnnotation *eachLocation in self.annotations) {
if([eachLocation coordinate].latitude > upper.latitude) upper.latitude = [eachLocation coordinate].latitude;
if([eachLocation coordinate].latitude < lower.latitude) lower.latitude = [eachLocation coordinate].latitude;
if([eachLocation coordinate].longitude > upper.longitude) upper.longitude = [eachLocation coordinate].longitude;
if([eachLocation coordinate].longitude < lower.longitude) lower.longitude = [eachLocation coordinate].longitude;
}
NSLog(#"Loc Upper: %f, %f", upper.latitude, upper.longitude);
NSLog(#"Loc Lower: %f, %f", lower.latitude, lower.longitude);
// FIND REGION
MKCoordinateSpan locationSpan;
locationSpan.latitudeDelta = upper.latitude - lower.latitude + 0.003;
locationSpan.longitudeDelta = upper.longitude - lower.longitude+ 0.003;
CLLocationCoordinate2D locationCenter;
locationCenter.latitude = (upper.latitude + lower.latitude) / 2;
locationCenter.longitude = (upper.longitude + lower.longitude) / 2;
MKCoordinateRegion region = MKCoordinateRegionMake(locationCenter, locationSpan);
return region;
}
Once after installing app I get this:
and after that I get this view:
Any idea what can be wrong?