Editable UIwebview in UIScrollView. Scrolling problem

I have an editable UIWebView in a UIScrollView.

I have disabled scrollview and failures in UIWebView to rely on UIScrollView scroll view only.

Every 0.1 seconds I have a timer that detects if the content of the UIWebView has changed since the last check. If so, and if the caret is greater than the given position, the offset for the scrollView will be updated and the result will be pretty good.

My problem is when I come back to edit the already written text.

The UIWebView scrolls its own view and the text disappears.

I would like to use UIScrollView.

Here are two pictures showing the problem:

EDIT: Here is a video showing the error: http://dl.dropbox.com/u/9666723/Bug.mov

Thanks for any help.