Could be a newer version of SQL Server that isn't supported by the older version of VS.

>Thank you very much Craig.
>
>But I'm still a little at a loss to understand why on the same PC I do have access to the corporate sql servers on the lan in VS2012 and not in VS2010, i.e in the "Choose Data Store" dialog in VS2012 it shows me sqlservers that it does not VS2010.