Auto Layout Top is not working well with 10px space at top

Question

I'm building iphone app. I use auto-layout. Please check following images.

As you can see, the top space is set as 0px. but in running, the top space is 10px.

I want to fix this issue asap. P.S. it is same on iOS7 & iOS8. Thanks,

Answer 1

Go to constraint->edit. Set both First Item and Second item to .top. And make sure it's not Relative to margin.