Why is EF returning a proxy class instead of the actual entity?

I'm having trouble with entity framework returning Proxies when I want the actual entity class. The first time I run my code everything runs properly (no proxies), but every iteration afterwards one of my DbSets always returns proxies instead of the actual type.

I dispose of the context after every iteration, so I don't understand why the first time through it works, and every time after doesn't.

My code fails on this line. All my POCOs have the Table attribute set, but because it is returning a proxy class there is no table attribute.

TableAttribute attrib = (TableAttribute)attributes.Single();

Is there some behind the scenes static magic in the DbContext that lives after I destroy the object?

I move my objects into memory using the following

MajorClasses = ctx.MajorClasses.ToArray();

I also tried

MajorClasses = ctx.MajorClasses.AsNoTracking().ToArray();

In my OnModelCreating I have the following set

base.Configuration.ProxyCreationEnabled = false;
            base.Configuration.LazyLoadingEnabled = false;