It is not fixed by Closing the popup manually when start scrolling.
As it was menctioned in the Link : http://www.telerik.com/support/kb/aspnet-ajax/combobox/details/the-dropdown-area-is-dispositioned-on-scroll-
content.onscroll = function()
var combo = <%= RadComboBox1.ClientID %>;
We are getting this issue when we are selecting the Rad Combo box without any scroll on the page.
we are facing this issue only in chrome browser.
Is there any solution without Upgrading to new version.