Tim although I'm not trying out security right this minute I did just try it on the Northwind database. The key seems to be that space between Data and Source. Here is the string that works:

key="Northwind\Connection" value="Data Source=\Projects\VistaMMTest\Data\NorthWind.vdb3;Database=Northwind;AccessMode=Local;Cyper=None;Password=; Exclusive=False;ReadOnly=False"