Hi Ron,
I had the same issue a while back. It can be annoying to get to work the first time - then it's the easiest thing in the World. I can't be sure without seeing your ASPX, but I'm guessing that your RadComboBox isn't posting back to the server after an item is selected. Until a postback occurs, you won't see whether the label has been updated server-side.
To that end, you can setup your RadComboBox like this:
However, why go through a postback if you don't have to? This is exactly the case that JavaScript was intended to solve. So, a superior solution is to change the label client-side and not postback the whole grid unnecessarily.
You can setup your RadComboBox like this:
and include the following JavaScript function.
JavaScript is your friend!
Hope this helps!
-Gimmik