Today, I booted up my computer and my tablet driver failed and “relaunching” the driver didn’t help at all. I figured Apple must have made an update that conflicted with the Wacom driver, leaving me to reinstall the latest driver, which I downloaded from Wacom here. Unfortunately I found reinstalling the driver did no good. I restarted. Uninstalled the driver. Reinstalled the driver. Restarted. Nothing. Same problem over and over; once I login the driver fails and when I go to my preferences pane it tells me that it is unable to find my USB tablet. Unplug USB. Reboot. Plug in USB. Nothing.

Eventually I was able to discover that while the new driver did not seem to work for my user account, it worked fine on my login screen and for my “admin” account. So at least I knew the problem was specific to my user configuration. Now, armed with this information and Google I was really able to get to the root of the problem with the help of this post by someone going by the handle rausch over a year ago.

Quick Answer

When uninstalling (which should be done before reinstalling) the pen tablet driver, the Wacom uninstall script fails to remove a few key files located in the ~/Library/Preferences/ directory:

com.wacom.pentablet.p.TMP
com.wacom.pentablet.prefs
com.wacom.tabletpreferences
com.wacom.wacomtablet.prefs

To fix the driver from failing, uninstall the driver — do this by holding down open-apple and clicking on the icon in the preferences pane. Then delete any of the above files that still exist in your ~/Library/Preferences directory — where “~” is your user directory (OS X recognizes this syntax). In my case I only need to delete two of the above files as they were the only two of the four still present in my ~/Library/Preferences directory. Reinstall the driver and with any luck, your tablet will function properly again. Keep in mind, this will reset your tablet preferences back to the default settings.

Thank you rausch, whoever you are. And I hope that by republishing these instructions, someone else will be able find a solution to their problem faster that I did.