The example you refer to is a simple demo that aims to demonstrate possible uses of RadToolTip, and especially how the tooltip can be controlled using its client-side API
. With this respect, the form at the example is not a "real" form that presentd a full-blown ready to use case.
The problem you refer to would exist whether you use a RadPanel (e.g. AJAX) or you use simple postbacks.
It is due to the way the HTTP protocol functions. What the example shows is adding items to list control a client-side. Please note, that such items do not get sent
to the server by default. In order to send those to the server, you would need some extra code - such as adding the items into a hidden field - whose [modified] value does gets sent on the server.
Please implement the scenario, and get it working using a hidden field + regular postbacks, and let us know if you encounter any problems with converting it to work with AJAX.
the Telerik team