Problem with UITextView and frame task

Question

Hi this is my UITextView coordinate on InterFace builder :

so if i want use this coordinate via frame task , my UITextView going to change the position on the screen !!! i don't know what's the problem ! i insert the exactly numbers on the interface builder size tab .

 textPad.frame = CGRectMake(511, 219, 751, 260);

what is the problem ?