Popping View crashes Application at [super dealloc] - iphone

Question

I have a tableView:didSelectRowAtIndexPath: where I create a ViewController-Instance each time an item is selected. Sometimes it works fine for a long time, sometimes it crashes with a EXC_BAD_ACCESS very quickly. The debugger blames the line [super dealloc]; in the QuestionDetailViewController.
Why? I log the QuestionDetailViewController retainCount. That looks fine.
QuestionDetailViewController
#import <UIKit/UIKit.h>
#import "Question.h"
#import "Answer.h"
#interface QuestionDetailViewController : UIViewController < UIScrollViewDelegate , QuestionDetailViewProtocol> {
Question *question;
UILabel *answerText;
UILabel *titleLabel;
}
#property(nonatomic,retain) Question *question;
#property(nonatomic,retain) UILabel *answerText;
#property(nonatomic,retain) UILabel *titleLabel;
#end
#import "QuestionDetailViewController.h"
#implementation QuestionDetailViewController
#synthesize question;
#synthesize answerText;
#synthesize titleLabel;
- (void)viewDidLoad {
[super viewDidLoad];
}
- (void)viewWillAppear:(BOOL)animated {
UIColor *bgColor = [UIColor colorWithRed:199.0/255 green:234.0/255 blue:251.0/255 alpha:1];
self.answerText = (UILabel *)[self.view viewWithTag:2];
self.answerText.backgroundColor = bgColor;
self.answerText.text = self.question.answer.text;
self.titleLabel = (UILabel*)[self.view viewWithTag:1];
CGSize sizeTitle = [self.question.title sizeWithFont:[titleLabel font]
constrainedToSize:CGSizeMake(280.0, INFINITY)
lineBreakMode:UILineBreakModeWordWrap];
self.titleLabel.text = self.question.title;
self.titleLabel.lineBreakMode = UILineBreakModeWordWrap;
self.titleLabel.frame = CGRectMake(10,10, 260, sizeTitle.height);
CGSize sizeText = [self.question.answer.text sizeWithFont:[self.answerText font]
constrainedToSize:CGSizeMake(280.0, INFINITY)
lineBreakMode:UILineBreakModeWordWrap];
self.answerText.frame = CGRectMake(0,20+sizeTitle.height, 310, sizeText.height+sizeTitle.height);
[(UIScrollView *)self.view setContentSize:CGSizeMake(280, answerText.frame.size.height +sizeTitle.height)];
self.view.backgroundColor = bgColor;
[super viewWillAppear:animated];
}
- (void)viewDidDisappear:(BOOL)animated {
NSLog(#"%d", [self retainCount]);
[super viewDidDisappear:animated];
[self release];
}
-(IBAction)goBack:(id)sender{
[self.navigationController popViewControllerAnimated:YES];
}
- (void)dealloc {
NSLog(#"QDC dealoc");
[self.answerText release];
[self.titleLabel release];
[self.question release];
[super dealloc];
}
#end
tableView:didSelectRowAtIndexPath:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
QuestionDetailViewController *qdc = [[QuestionDetailViewController alloc] initWithNibName:#"QuestionDetailViewController" bundle:nil];
Question* question;
if ([filteredQuestions count]>0) {
question = [self.filteredQuestions objectAtIndex:indexPath.row];
} else {
question = [self.questions objectAtIndex:indexPath.row];
}
[qdc setQuestion:question];
[question release];
NSLog(#"%d", [qdc retainCount]);
[self.navigationController pushViewController:qdc animated:YES];
[qdc release];
}

Answer 1

This:
- (void)viewDidDisappear:(BOOL)animated {
NSLog(#"%d", [self retainCount]);
[super viewDidDisappear:animated];
[self release];
}
looks incredibly suspicious. Did you do [self retain]? If not, then why are you releasing? If you are, you're probably doing something wrong, because [self retain] is an incredibly rare thing to need to do.

Answer 2

Instead of:
[self.answerText release];
[self.titleLabel release];
[self.question release];
use:
self.answerText = nil;
self.titleLabel = nil;
self.question = nil;
or:
[answerText release]; answerText = nil;
[titleLabel release]; titleLabel = nil;
[question release]; question = nil;