I am writing this because it is fresh in my mind because I have had the exact problem with a client. They had an old Access database that they needed to get data into on 64bit QlikView. Now, I have a 64bit Access driver because I have 64bit Office 2010 and it works great in QlikView. Microsoft have released this as a separate download so you don't need office installed on your server:
You don't need newer format Access databases, it works with older mdb files too. Only criticism that I have is that the DataLinks properties box doesn't have an ellipse button to allow you browse for your database. This isn't the most difficult thing to get past, just paste the path into the properties box.
Hope this helps.