Problem with saving attached Entity with Entity Framework

[Assassyn]

When you load entity, commit the unit of work, after the change attempt on such entity there is no way to attach(reattach) it to context and submit changes to database. I have problem when I was using IEntityWithKey but I suppose that similar problem can happens for POCO type of entities.

Problem could be resolved by adding:
public void Attach(T entity) where T : class
{
//If the entity implementes the IEntityWithKey interface then we should use Context's Attach metho
//instead of the set's Attach. Getting an exception
//"Mapping and metadata information could not be found for EntityType 'System.Data.Objects.DataClasses.IEntityWithKey"
//when using set's Attach.
var entityWithKey = typeof (IEntityWithKey);
if (entityWithKey.IsAssignableFrom(entity.GetType()))
{
_context.Attach((IEntityWithKey)entity);
// new line seem to solve the problem
_context.ObjectStateManager.ChangeObjectState(entity, EntityState.Modified);
return;
}

        GetObjectSet<T>().Attach(entity);
        //_context.DetectChanges(); //Required for POCO entities
    }