What type of application are you testing? Is it a Silverlight application or an HTML? Looking the code you provided, the methods you're currently using are not from Telerik Testing Framework. In order to better understand your scenario and help you writing the code could you please provide a copy of your test and access to your application? If direct access to your application is not possible you can point us to a sample public app which contains similar Tab controls. Alternatively you can take a Fiddler trace using FiddlerCap
and send it to us in a zip file. Basically with that trace I'll try to "simulate" your app in order to reproduce the issue. Thanks for providing the info we need to best assist you.
the Telerik team