Created Unassigned: Stops responding (crashing) when reading data [1965]

I have a serious problem with Composite C1 (Build no. 4.1.5058.34326) using SQL Server.

I've added numerous global data types, among these a login feature. The login feature uses a data type called Login, that consists of: EmailAddress (string), Password (string), IsActivated (bool).

IsActivated is by default False, when I try to query:

TriGemini.Login dbLogin = null;
using (DataConnection connection = new DataConnection())
{
dbLogin = (from n in connection.Get<TriGemini.Login>()
where n.EmailAddress == email &&
n.Password == password &&
n.IsActivated
select n).FirstOrDefault();
}

I actually get all records - with no respect to the value of IsActivated (I've even tried n.IsActivated == true).
So eventually I tried removing the n.IsActivated from my LINQ expression and simply on my page trying to write out the value of IsActivated. Then the site simply hangs - no information in the server log - only way to regain life is to use the "Restart Server" from the console or restarting the web site via the IIS.

And no I'm not using caching on the datatype. What could be going wrong here?