iphone到ipad，iphone 4 uialertview问题

So I've upgraded the code to the ipad (i.e. converted to a universal app). However, the UIAlertview rendering seems to be off for IOS4. Instead of being positioned in the middle, it jumps up and is displayed on top, with half the box cut off. Same goes for landscape orientation. So I've upgraded the code to the ipad (i.e. con