Well, very interesting... i just found a solution, it´s something about the schema cache...
Here is what I did:
- Close VS,
- delete schema cache,
- re-open VS.
You can find the schemas under something like:
or in my case something like:
C:\Documents and Settings\hernandr\Application Data\Microsoft\VisualStudio\10.0\ReflectedSchemas
deleted all files, reopen VS.. and... voila... problem fixed...
Here is the original post where I found it: http://forums.asp.net/p/1552731/3811467.aspx)
Hope this helps,