Hello Andy,
I am not aware of the problem you report but a lot of improvements were made and bugs were fixed since the Q3 2008 version of RadControls you use and that is why it is possible that the problem you face is already solved in the new version. That is why I suggest to wait until our Q2 2009 build is available which is scheduled for these days, upgrade to it and test whether the issue is resolved.
In case the upgrade does not help, please provide more details about the issue along with some of your code and we will do our best to help.
Kind regards,
Svetlina
the Telerik team