I have the following code snippets:

@interface PinRecordNewTableViewController : UITableViewController {
}
... 
@implementation PinRecordNewTableViewController
...
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
...
        PinRecordNewPicture *pinRecordNewPicture = [[PinRecordNewPicture alloc] initWithNibName:@"PinRecordNewPicture" bundle:nil];
        pinRecordNewPicture.delegate = self;
        [self.navigationController pushViewController:pinRecordNewPicture animated:YES];    
        [pinRecordNewPicture release];  
...             
}
@interface PinRecordNewPicture : UIViewController 
...
@implementation PinRecordNewPicture
...

- (void)picturePicker:(UIImagePickerControllerSourceType)theSource {

UIImagePickerController *picker = [[UIImagePickerController alloc] init];

picker.delegate = self;
picker.sourceType = theSource;
picker.allowsEditing = YES;

[self presentModalViewController:picker animated:YES];

[picker release];

}

- (IBAction) takePicture:(id)sender {

UIImagePickerControllerSourceType source = UIImagePickerControllerSourceTypeCamera;

    if ([UIImagePickerController isSourceTypeAvailable:source]) {

       [self picturePicker:source];

    }

It works 80% of the time -- I could get the picture correctly.

The problem is that it occasionally failed to take a picture. When tracing the code, I found out that it occasionally goes to -PinRecordNewTableViewController:viewDidUnload. This is where it fails because it set nil to all ivars.

What did I do wrong? Did I miss something so it behaves "randomly"?

Thanks in advance for your help.