yes I have face same problem but my case is different than you .
You should try [textfield.text isEqualToString:@""]; because this is the standard way to compare empty text field in Objective-C.
Check that you dismiss your alert view properly sometimes we don't give focus on dismissing the alert view so because of that your alert view remain active and when you reopen you are app it shows 2 to 3 times depending on your condition. So you can use the delegate did dismiss alert view with button index for dismissing the alert view in view did disappear. I am not sure but it should work for you Good luck dude.
And I am not sure but I think your IBAction Button is overwrite for each time when you clicked in any button so you should check it also.
