The only difference between v4 and v3 is that I change the reference for SQL Server and modify the app.config file (look at the bottom of the config file).
I have this in the app.config file for v4:
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0" />
I have this in the app.config file for v3
<supportedRuntime version="v2.0.50727" sku="Client"/>
I uploaded my v4 VS project here:
Let me know if you have any questions.