System.TypeLoadException: Could not load System.Security.FrameSecurityDescriptorWithResolver from assembly mscorlib 4.0.0.0

So I am running into a situation where I have a deployed .net 4.0 (x86) winforms application deployed to a number of clients in our organization.  This week a new employee started and received a newly imaged Windows 7 machine, which should be identical to the machines of the other users, except that when we deploy to this particular machine we get the following exception:

System.AggregateException: One or more errors occurred. ---> System.TypeLoadException: Could not load type 'System.Security.FrameSecurityDescriptorWithResolver' from assembly 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.
   at NHibernate.Linq.DefaultQueryProvider.ExecuteQuery(NhLinqExpression nhLinqExpression, IQuery query, NhLinqExpression nhQuery)
   at NHibernate.Linq.DefaultQueryProvider.Execute(Expression expression)
   at NHibernate.Linq.DefaultQueryProvider.Execute[TResult](Expression expression)
   at System.Linq.Queryable.First[TSource](IQueryable`1 source)
   at Ipds.Dot.Dal.WorkAreaFuncs.GetWorkArea(Guid workAreaId)
   at Ipds.Dot.UI.WorkAreaSplashScreen.<>c__DisplayClass4.<.ctor>b__0(Object task)
   at System.Threading.Tasks.Task`1.InvokeFuture(Object futureAsObj)
   at System.Threading.Tasks.Task.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()
   --- End of inner exception stack trace ---
---> (Inner Exception #0) System.TypeLoadException: Could not load type 'System.Security.FrameSecurityDescriptorWithResolver' from assembly 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.
   at NHibernate.Linq.DefaultQueryProvider.ExecuteQuery(NhLinqExpression nhLinqExpression, IQuery query, NhLinqExpression nhQuery)
   at NHibernate.Linq.DefaultQueryProvider.Execute(Expression expression)
   at NHibernate.Linq.DefaultQueryProvider.Execute[TResult](Expression expression)
   at System.Linq.Queryable.First[TSource](IQueryable`1 source)
   at Ipds.Dot.Dal.WorkAreaFuncs.GetWorkArea(Guid workAreaId)
   at Ipds.Dot.UI.WorkAreaSplashScreen.<>c__DisplayClass4.<.ctor>b__0(Object task)
   at System.Threading.Tasks.Task`1.InvokeFuture(Object futureAsObj)
   at System.Threading.Tasks.Task.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()<---

We are a bit stumped as to why this is occurring on this one machine.  Could it be a bad .NET install or are there other things we might look into?