Bind to just parameters

[Keith]

Is a have a report created which shows a basic shape and a textbox with the value of [= Parameters.SomeParameter.Value].

I have code in my Silverlight client which passes the param as 

args.ParameterValues.Add("SomeParameter", "Some text");

in the RenderBegin event.  This code fires off, but I just receive an error from the Silverlight Report Viewer of:

One or more parameters are not set or have invalid values.

Can I bind to just report parameters?  I am doing this because it is ungodly hard to pass over my objects for the report from the Silverlight client.

[Keith]

Had to refactor this completely to pass my params into the constructor.  Once I took the async callback to get data out of the equation all was well.