iOS iPhone can't open generated/saved KML file with Google Earth App

Question

with the following code i try to open a generated and saved KML file in Google Earth App.

Google Earth app opens but it do nothing.

When i send this file with email and open it with GE App it works fine. is there a way to open mml from my app in GE?

That the url i try to open: kml:///var/mobile/Applications/****/Documents/google_earth.kml

here the code:

    NSError *error;
    BOOL success;

    //get the documents directory:
    NSArray *paths = NSSearchPathForDirectoriesInDomains
    (NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSString *fileNameKML = [NSString stringWithFormat:@"%@/google_earth.kml", documentsDirectory];
    NSString *GoogleEarthfileName = [NSString stringWithFormat:@"kml://%@", fileNameKML];
    //NSLog([NSString stringWithFormat:@"Google Earth filename: %@", GoogleEarthfileName]);

    NSURL *newURL = [NSURL URLWithString:GoogleEarthfileName];
    success = [kmlExport writeToFile:fileNameKML atomically:YES encoding:NSUTF8StringEncoding error:&error];
     if (success){
         if ([[UIApplication sharedApplication] canOpenURL:newURL])
         {
             [[UIApplication sharedApplication] openURL:newURL];
         }
         else
         {
             UIAlertView * alertView = [[[UIAlertView alloc] initWithTitle:@"Google Earth not installed" message:@"Please install Google Earth to view your tracked route." delegate:self cancelButtonTitle:NSLocalizedString(@"TXTOK", nil) otherButtonTitles: nil] autorelease];
             [alertView show];
         }
    }

Thanks Kevin