Can you use a different comp to set up the drive mapping? That way you can tell if its the comp or the printer. From what Ive read it seems like its the comp but its good to know for sure.
Ummm Im gonna throw some stuff against the wall and hope that something sticks.
Have you set the drive sharing to only share with one user at a time? If so disable that for now and see if it works.
What OS are you using?
Maybe something on your computer has a resource leak. Try old drivers, new drivers, make sure they are for your OS.
Try reinstalling the software.
Try installing on a fresh comp that you havent used to interact with the printer before if possaible. :/