query_posts() inside post-new.php

Hello.

I’m trying to display a select in a metabox for a custom-post-type posts (type A). That select would include all the title posts from other custom type (type B), just to associate them.
The problem is that when I use query_posts() to retrieve all the type A posts, all the other fields in post-new.php (title, editor…) get filled with the information of the last item in the query.
How could I keep that query independent of the global loop?

Thanks so much.