If you mean that the user is able to scroll the page off-screen, and then it bounces back, this is Mobile Safari behavior which cannot be overridden for websites or webapps.
If you are creating a native app using PhoneGap, etc. then this is a property of the WebView that can be changed. But Apple does not expose this through Javascript, so not possible for websites.
I find it hard to find this a "problem", given that it's standard behavior that users expect.
But if it bothers you that much, and you aren't creating a native app, you can use iScroll to scroll the list content, and the prevent scrolling of the page itself altogether. iScroll has options to control it's bounce behavior, and so if it bother you you can turn it off. It
If you are talking about something else, you will have to show us what you mean.