February 23, 2009 by Tap
According to a thread on the Google Mobile support forum, there seems to be a bug that prevents paid Android Market applications from being updated. According to the thread, "After you purchase a paid [application] and and then try to update it, it doesn't update. It just says downloading and nothing happens." This bug only affects paid apps. Free apps are not affected.
Google's response - "Thanks for reporting this to us - just wanted to let you know we're looking into it."
Via: Google Mobile Help Forum