I have miserable and hard-to-belive problem:
However, it does't happen... Any ideas?
I'd recommend one of a view things:
Check your main view has its own resizing set to have flexible height.
Check that your view doesn't have autoresizing flexible top and bottom margins.
You say that this is a "control" - if it is a UIKit control, its probable that Apple doesn't allow changing it to have flexible heights. Take for example UISwitch. A flexible switch couldn't resize width or height as it is system drawn for its size. This may apply to any other UIKit-defined control where the autoresizing mask isn't appropriate to it's display.