Ok, I found a workaround around the problem, but it still doesn't solve the issue. The default folder that's opened when I click on "save as" is my documents folder. I moved the contents of that folder (AIM fileib folder) into another folder, then the freezing problem stopped. I don't understand why that fileib folder would cause freezing, since it only contains another empty subfolder. The funny thing is after I moved the fileib folder, I can navigate from my "documents" folder to that fileib folder without freezing.