iphone - UIView is shown displaced at the top of the screen -

ok, stupid question newbie...

i have app used display fine base on xib files created in ui builder. .xib still displays fine using simulator direct uib when compiled , run, view displaced 40 or 50 pixels (about 1/3 width of nav bar) bar of white space @ bottom , half title text hidden on nav bar @ top.

i have tried fiddling various parameters view , main window (eg layout wants full screen , resize view nib) nothing seems make difference.

i tried upgrading xcode 3 4 no difference.

any pointers gratefully received...

i don't know specific scenario, layout problems boil down inappropriately specified autosizing parameters.