I need help with TVAlue and IsObject and IsObjectInstance.

I need help with TVAlue and IsObject and IsObjectInstance.

So, I have a Dictionary with . The idea is to store different types of data linked to tags.
I now write
dictionary.add('John', '123);
dictionary.add('John List', myStringList);

When I want to retrieve 'John List' I go this:
newList:=dictionary.Items['John List].AsType;

Now, I want to free the dictionary and before this I iterate the items and free them.

Depending on the use, myStringList may be freed somewhere else in the code. So, I do this:

var
tmpValue: TValue;
tmpObject: TObject;
begin
for tmpValue in dictionary.Values do
if tmpValue.IsObject then
begin
tmpObject:=tmpValue.AsObject;
if Assigned(tmpObject) then
FreeAndNil(tmpObject);
end;
end;

Now, if I don't free myStringList this code works correctly. If the list is Freed (or FreeAndNil) the if IsObject is always performed and, also, the if Assigned.

I have tried with IsObjectInstance (which would make more sense) but I get the same behaviour.

Any ideas what I do wrong with this?

Thanks