Dynamic Marketing List Query

Hi All,

I am wondering if there is a bug in Dynamic Marketing List Query. 

There are two marketing lists with contacts. When I want to get contact from both lists, query is " List equals <List1> OR List equals <List2>". That does produce the list I expect.

However, when I want to get only members from first list, which are NOT members of list 2, the query I use " List equals <List1> AND List does not equal <List2>". That produces all contacts from list 1.

So how do I select ONLY members from LIST1 which do not belong to the LIST2?

Regards.