0 results on query even though rows exist in Database = 2 databases, but why 2?

I'm using Entity Framework (4.3) and code first (along with SQL server 2012 localdb).

I'm having an interesting situation where in one application a call returns a result ('card') and another using the same query on the same db (with thousands of rows available) returns nothing (null in this case since I'm using FirstOrDefault).

using (var context = new MyEntities())
        {
            //verify account exists
            var account = context.Account.SingleOrDefault(a => a.AccountNum == accountNum);

            if (account == null)
            {   
                //handle no account                 
                return false;
            }                

            var card = context.cards.FirstOrDefault(c => c.Used == false);

            //check that we actually got a card
            if (card == null)
            { 
                //handle no cards available
                return false;
            }

            card.Used = true;

           //snip...

            context.SaveChanges();
        }

In my test console app 'card' will have a value, while in my "service" it does not. Same code (same assembly even), same db, same rows available. The account retrieval works in both cases.

But even if that works the inconsistent behaviour doesn't make sense to me.

EDIT:

Ends up I have two database instance as pointed out. The interesting part is the datasource changes depending on where the library is run from (as debug under VS11 or from a service running as the admin user). Here's my app.config:

<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework">
  <parameters>
    <parameter value="Data Source=(localdb)\v11.0; Integrated Security=True; MultipleActiveResultSets=True" />
  </parameters>
</defaultConnectionFactory>

When I attached to the service process running the same library (DLL) as the console application the datasource has changed from:

(localdb)\v11.0

To:

.\SQLEXPRESS

Same DLL, same app.config. I vaguely remember reading something about named vs unamed local db instances and what user they are run under, however my google skills are failing me currently.

So when I open a connection in SSMS I need to use the appropriate server name depending on which db I'm working with. Not a big deal as this is just the setup for development.

My question:

• Does anyone know where this is documented?