Does it compile ???

If not ::

'myUseruc.myUser' is a class not an object or control.

So it looks like you may have a different version of your assembly still registered with the framework.
This can happen when you start  renaming assemblies and namespaces and so forth, or moving stuff baout.

Try changing the name of the class or namespace and recompile. It should work.

If that works, rename things back again and use gacutil to get rid of old assemblies in the cache and manually delete older versions with a different name. Redo all of your references  to dll's if you need to.