First, make sure that you have IE set to default zoom level. The highlighting for the item in your provided screen shot is off slightly, and this is caused either by the zoom being off for the browser (IE), or by having the DPI setting adjusted to a setting other than the default of 96 DPI. Please use our KBase article on Highlighting for steps on how to check/resolve this facet.
From the looks of the screenshot, this appears to be a Silverlight control. If this is the case, we are aware of an issue with the DOM not updating after postback on a Silverlight control. In this type of scenario, add the following coded step after you cause the postback but before you look for the element:
SilverlightApp slapp = ActiveBrowser.SilverlightApps();
SilverlightApp = ActiveBrowser.SilverlightApps()(0)
I wasn't sure which language you are using, so I provided both. Feel free to personalize the coded step for your test. Please let us know the results, we will look for your reply.
the Telerik team