为什么我的TabBarController隐藏了我的UIActionSheet？

I am having a problem correctly implementing a UIActionSheet in an iPad 5.1 (XCode 4.3) project. I can populate it correctly with all the items I need. The list is longer than the window, but the scrollbars automatically come up, etc. However, the cancel button (which I presume is supposed to be at the end) is coming up half hidden behind my tab bar. Shown below:I am having a problem correctly implementing a