There is a bug with the rendering of the kendoDropDownList When having a site with the following structure: <body> <div id="site"> <-- other content --!> </div> </body> The site div is streched to support a footer appearing at the bottom: #site { min-height: 100%; height: auto !important; height: 100%; } The first time you open the dropdown box it will appear 9.5 px to the left then where is supposed to be, the second time it appears correct.
This issue has been fixed since the Kendo UI Q2 2012 release.
The given information is not sufficient to reproduce the issue. I will suggest you open support/forum thread and provide a simple jsFiddle demo which replicates the issue.