This happened to me even with the new 3.0 Shareport software.
I've had the DIR-825 for about 7 months. The software available at the time I bought the unit worked for about a week, then stopped. I was able to get it working every couple of weeks but eventually gave up.
I just found out about version 3.0 two weeks ago and thought it would have fixed the problem, and I thought it did because it worked well over a week. Then today I went to use it and it's stopped working. Even worse, when I physically disconnect my printer's USB cable from the router, it still appears on my Shareport software, EVEN AFTER REBOOTING THE ROUTER through the web browser interface.
I have left the router and printer on and connected for over a week, so I don't know if the router eventually gets the printer's information STUCK somehow?
Please reply to this thread if you figure out a solution. I'll be checking for updates to the router's firmware and Shareport Utility.