I'm using a UILabel for the titleView of a navigation bar (I'm making simple in-app web browser). It works fine, except that when I present a modal view controller, the titleView shifts from the center of the navbar to the far left (underneath the back button). I've tested in 3.0 and up. Here is relevant code:

- (void)viewDidLoad {
    [super viewDidLoad];
    // Title view label
    CGRect labelFrame = CGRectMake(0.0, 0.0, 120.0, 36.0); 
    UILabel *label = [[[UILabel alloc] initWithFrame:labelFrame] autorelease];
    label.font = [UIFont boldSystemFontOfSize:14];
    label.numberOfLines = 2;
    label.backgroundColor = [UIColor clearColor];
    label.textAlignment = UITextAlignmentCenter;
    label.textColor = [UIColor whiteColor];
    label.shadowColor = [UIColor blackColor];
    label.shadowOffset = CGSizeMake(0.0, -1.0);
    label.lineBreakMode = UILineBreakModeMiddleTruncation;
    self.navigationItem.titleView = label;
}

-(void)displayComposerSheet:(NSString*)mailto 
{
    MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
    picker.mailComposeDelegate = self;
    [self presentModalViewController:picker animated:YES];
    [picker release];
}

Screenshots: http://img689.imageshack.us/img689/7968/titleviewshift.jpg

Any idea why this is happening? Thanks.