I know that the presence of the more view controller (navigation bar) pushes down the UIView by its height. I also know that this height = 44px. I have also discovered tha
Here is the beginning of my response to your update:
Why does the content height of my UIWebView not change with rotation?.
Could it be that because your auto resize doesn't have the autoresizingMask for all directions?
Another suggestion before I come back for this, could you use a toolbar for your needs. It's a little simpler, will always be on the bottom, auto-rotates/positions. You can hide/show it at will etc. Kind of like this: http://cdn.artoftheiphone.com/wp-content/uploads/2009/01/yellow-pages-iphone-app-2.jpg
You may have looked at that option, but just throwing it out there.
Another idea, could you possibly detect what orientation you are rotating from, and just place the button programmatically to adjust for the tab bar. (This is possible with code)