App crashing after reloading

Question

I am writing my first app that tries to deal with persistent data and am having some major troubles. I finally feel like I am getting close but now the crash is crashing sporadically - I assume it is some sort of memory issue but have no clue how to fix it. If I reset the settings of the iphone simulator and then run the app it works great for quite a while. Then if i close the simulator and re-run the app, it will crash when this method is called:

-(IBAction)selectedProfile {

NSInteger rowSelected = [profilePicker selectedRowInComponent:0];
NSUserDefaults *profiles = [NSUserDefaults standardUserDefaults];

if(rowSelected == 0) {
    [profiles setInteger:1 forKey:@"activeuser"];
} else if (rowSelected == 1) {
    [profiles setInteger:2 forKey:@"activeuser"];
} else if (rowSelected == 2) {
    [profiles setInteger:3 forKey:@"activeuser"];
}
[profiles synchronize];


FormsViewController *rootVC = [[FormsViewController alloc] init];

UINavigationController *theNavController = [[UINavigationController alloc]
                                             initWithRootViewController:rootVC];

theNavController.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[self presentModalViewController:theNavController animated:YES];

[rootVC release];
[theNavController release];

}

I am wondering if it has to do with the way I am dealing with the persistent data because I didn't have this problem prior to implementing it. The user is given a UIPickerView with 3 options and the rest of the app is dependent on which of those 3 options the user chooses. Could it be the persistent data?