What do you mean it's no longer updated ? Does this mean you lose what was displayed before switching or it doesn't update anymore. If it's not updating anymore it's because you don't start the timer in the appropriate method. You could do something like :
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self startLastConUpdater];
}
This should solve both issues I mentioned above.