Why UIImageView moves from its original place (interface builder) during runtime?-Collection of common programming errors

I have placed 3 images into UIImageViews using xcode4 interface builder: background, and two pictures. Background image fills the whole visible area and it looks the same in interface builder, in simulator and on device. In addition, I’m placing another image at the very bottom (stick to) of visible area, and another one on top of it. Both looks as I want in interface builder. The problem is both bottom image and on top of bottom image moves approximately by 50 pixels up when running in simulator or iphone4 device. Interesting part is that background image fill whole visible area. I should note that I’m using UIInterfaceOrientationLandscapeRight orientation so the status bar in my orientation should appear on top but I have disabled it in plist, so I guess it’s not related to this problem. Both of my problematic UIImageView’s have mode “Bottom”. Also, all of three images have @2x image twin. But why can see everything OK in interface builder and then some shift on simulator and device? Also, strange why background is not moved. Does anybody had the same problem?