Just to follow up for anyone following the thread -
I provided Petya with some sample code through the support ticket threads. Here's what I got in response.
Date: 6/20/2007 7:04:01 AM
Thank you for providing us with a simplified version of your code. Even simplified to this extend it is not of a small amount, so I hope that I am not missing something and the suggestion I will offer you to solve your problem will be an appropriate one. Please, place an asp:updatepanel around all the content in WeatherBox.ascx. I hope you find this solution satisfactory.
All the best,
the Telerik team
Date: 6/20/2007 10:18:46 AM
Thanks so much, Petya...
I love it when the solution is simple, though it makes me feel like a big dummy I've banged my head for so long on it!