Cant' navigate to nib iphone sdk-Collection of common programming errors

This is my code to navigate to another nib,

  MaintenanceViewController *maintenance = [[MaintenanceViewController alloc] initWithNibName:@"MaintenanceViewController" bundle:nil];

    CGRect theFrame = maintenance.view.frame;

    theFrame.origin = CGPointMake(self.view.frame.size.width, 0);

    maintenance.view.frame = theFrame;

    theFrame.origin = CGPointMake(0,0);

    [UIView beginAnimations:nil context:nil];

    [UIView setAnimationDuration:0.6f];

    maintenance.view.frame = theFrame;

    [UIView commitAnimations];

    [self.view addSubview:maintenance.view];

note that I am not using navigation controller and also I dont want to as my app is not based on navigation.

When This method is called on second line i.e. getting frame(theframe) the app got crashed with error Exec_bad_access code=2 address = 0xbf7ffffc.

So nib couldn’t loaded.