Thanks to Michael Pollock, my problem is solved. Here’s the workaround:
step 1: export the text file from quickblog.
step 2: open the text file in a text editor and do a find and replace. you want to find the word “Published” and replace it with just “Publish”. save the file.
step 3: import the file as a Moveable Type/Typepad file.
if you don’t change Published to Publish, the posts will be imported into the database, but they won’t show up anywhere in your WordPress control panel. then you’ll have to go into the database and dump all the posts you just imported.