If I import your code in it's entirety to one of my projects, and supply the missing "}" and the necessary using statement:
using System.Data.SqlClient;
It compiles without error or warning on my system (VS 2010 Pro).
So the error has to be elsewhere.
First, try shutting down VS. Then reopen your solution, Clean it, and do a full rebuild. Does the problem persist?
Then look at your other files: Anything else that is called StatusUser?
Try changing the name of your class to XXStatusUser (and manually change teh references in that one file) Problem still there?