Hello Brandon Strevell,
Silverlight 4 doesn't support Bindings in Style setter.
With the RC release the parser now throws exception (in SL 3 it was ignored).
We have workaround for this - ContainerBindingCollection where you specify Binding for each property of the container (in this case RadMenuItem) that have to be bound.
You can see an example with source code here:
Let us know if you need more information.
the Telerik team
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