this is a very common issue in SilverLight beta 2,
to solve this,
1. you have to enable includeExceptionDetailInFaults to true
2. Download firebug, and inspect the issue, or the error code.
3. Search the error code in google ;)
4. if it's "415 - Unsupported media type" then only thing u have to do it change the
binding="wsHttpBinding" to binding="basicHttpBinding" in .conig file ..
DISCO it works!!!
