Hello Patrick,
I seem to get my properties defined with the instance keyword (though I dont
know what it leans in IL).

I do:

Dim tFieldBuilder As FieldBuilder = Nothing
Dim tPropertyBuilder As PropertyBuilder = Nothing
Dim tMethodBuilder As MethodBuilder = Nothing

tFieldBuilder = tTypeBuilder.DefineField("sSomeString", tType, FieldAttributes.Private)
tPropertyBuilder = tTypeBuilder.DefineProperty("SomeString", System.Reflection.PropertyAttributes.None,
tType, Nothing)
tMethodBuilder = tTypeBuilder.DefineMethod("get_SomeString", MethodAttributes.Public
Or MethodAttributes.SpecialName, tPropertyBuilder.PropertyType, New Type()
{})
tILGenerator = tMethodBuilder.GetILGenerator
With tILGenerator
    .DeclareLocal(tPropertyBuilder.PropertyType)
    .Emit(OpCodes.Nop)
    .Emit(OpCodes.Ldarg_0)
    .Emit(OpCodes.Ldfld, tFieldBuilder)
    .Emit(OpCodes.Stloc_0)
    .Emit(OpCodes.Ldloc_0)
    .Emit(OpCodes.Ret)
End With
tPropertyBuilder.SetGetMethod(tMethodBuilder)