Hello Phill Hodgkinson,
Thank you for getting back to us.
We are aware of this forum thread, and have tried to reproduce the issue however to no avail. We have started working on your support ticket also. I have tried the code that you have sent and it does not break on my side, so we need a little bit more time to investigate the issue. I have attached a screen cast that shows how the control you have sent behaves on my side (I am using the configuration for my site as from my previous posts). If the video wont play in media player try viewing it in a browser.
As I mentioned above we are currently investigating your issue. Once we are done trouble shooting and have some answers and suggestions we will get back to you. I think that we will be able to respond to you by the end of the day.
All the best,
the Telerik team