First up is the ASP.Net MVC 3 EF4.1 code. Multiple sets of objects for each type are not supported

I wanted to use the first sample EF 4.1 code that could be tested per unit. I followed the sample code illustrated in the answer to This Post . But now I get the error message "Multiple sets of objects for each type are not supported." I also use the latest Structure Map for IoC. I am not sure how to solve this problem.

Many sets of objects for each type are not supported. Participant Types and Participant Types object sets can both contain instances of type 'SocialSite.Model.Entities.MemberType'.

Line 82: public virtual IEnumerable<T> FindAll()
Line 83: {
Line 84:     return _dbSet.ToList();
Line 85: }
Line 86: 

[InvalidOperationException: Multiple object sets per type are not supported. The     object sets 'MemberTypes' and 'MemberTypes' can both contain instances of type     'SocialSite.Model.Entities.MemberType'.]
   System.Data.Entity.Internal.DbSetDiscoveryService.RegisterSets(DbModelBuilder     modelBuilder) +336
   System.Data.Entity.Internal.LazyInternalContext.CreateModelBuilder() +393
   System.Data.Entity.Internal.LazyInternalContext.CreateModel(LazyInternalContext     internalContext) +22
   System.Data.Entity.Internal.RetryLazy`2.GetValue(TInput input) +117
   System.Data.Entity.Internal.LazyInternalContext.InitializeContext() +407
   System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +17
   System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +62
   System.Data.Entity.Internal.Linq.InternalSet`1.GetEnumerator() +15
   System.Data.Entity.Infrastructure.DbQuery`1.System.Collections.Generic.IEnumerable<TResult>.GetEnumerator() +40
   System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +315
   System.Linq.Enumerable.ToList(IEnumerable`1 source) +58
   SocialSite.Data.Repositories.Impl.Repository`1.FindAll() in D:\Visual Studio 2010\SocialSite\SocialSite.Data\Repositories\Impl\Repository.cs:84
   SocialSite.Service.Impl.MemberTypesService.GetMemberTypes() in D:\Visual Studio 2010\SocialSite\SocialSite.Components\Impl\MemberTypesService.cs:23
   SocialSite.Web.Areas.Admin.Controllers.MemberTypesController.ListMemberTypes() in D:\Visual Studio 2010\SocialSite\SocialSite\Areas\Admin\Controllers\MemberTypesController.cs:44
   lambda_method(Closure , ControllerBase , Object[] ) +62
   System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +17
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +208
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27
   System.Web.Mvc.<>c__DisplayClass15.<InvokeActionMethodWithFilters>b__12() +55
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +263
   System.Web.Mvc.<>c__DisplayClass17.<InvokeActionMethodWithFilters>b__14() +19
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +191
   System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +343
   System.Web.Mvc.Controller.ExecuteCore() +116
   System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +97
   System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +10
   System.Web.Mvc.<>c__DisplayClassb.<BeginProcessRequest>b__5() +37
   System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +21
   System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +12
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
   System.Web.Mvc.<>c__DisplayClasse.<EndProcessRequest>b__d() +50
   System.Web.Mvc.SecurityUtil.<GetCallInAppTrustThunk>b__0(Action f) +7
   System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) +22
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +60
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8862381
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184

not sure how to format the stack trace with any berterter than this.

, .

public class MemberType
{
    [Key]
    public virtual int Id { get; set; }

    [StringLengthAttribute(65, ErrorMessage = "Maximum length 65 characters")]
    public virtual string Name { get; set; }

    public virtual string Description { get; set; }

    public virtual bool Registration { get; set; }

    public virtual bool Enabled { get; set; }

    [TimestampAttribute]
    public virtual byte[] Timestamp { get; set; }

    public virtual bool Activation { get; set; }

    public virtual Guid RoleId { get; set; } // TODO: this should be a complex type of aspnet_Role or atleaset a foriegn key

    public virtual bool Searchable { get; set; }

    public virtual ICollection<MemberTypeProfileFieldGroup> MemberTypeProfileFieldGroups { get; set; }
}