SimpleIOC and generics

Question

I'm trying to generalize some code so that it can be used between projects, but I'm having some trouble generating instances from templated classes.

public class GenericRepository<TEntity, TContext> : IGenericRepository<TEntity>, IDisposable
    where TEntity : class
    where TContext : DbContext, new ()
{
    protected TContext Context;

    public GenericRepository()
    {
        Context = new TContext();
    }

    public virtual TEntity Create()
    {
        return Context.Set<TEntity>().Create();
    }

    // etc.
}

public interface IPlan
{
    int PlanId { get; set; }
    string Name { get; set; }
    DateTime Modified { get; set; }
    DateTime Created { get; set; }

    event PropertyChangedEventHandler PropertyChanged;

}

public partial class Session : DataErrorInfo, INotifyPropertyChanged, IPlan
{
    // Stuff to implement IPlan
}

IPlan and Generic repository are in the common code base, and Session is project-specific. So I want to be able to do something like this:

   // These both work correctly
   SimpleIoc.Default.Register<IPlan, Session>();
   SimpleIoc.Default.Register<IGenericRepository<Session>, GenericRepository<Session, EMTVSEntities>>();

   // Tried this one ...
   SimpleIoc.Default.Register<IGenericRepository<IPlan>, GenericRepository<Session, EMTVSEntities>>();

Ultimately what I want is to be able to call this last one and get the context like this ...

var ctx = ServiceLocator.Current.GetInstance<IGenericRepository<IPlan>>();

But I get the following message: Unable to cast object of type 'GenericRepository2[Session,EMTVSEntities]' to type 'IGenericRepository1[IPlan]'.

I understand it can't match the two types to do a case, but is there a way to get a specific instance from one identified by an interface using the templated type GenericRepository?