It sounds like you're not getting any of the extra data in ArtRage. Unfortunately the problem here will be related to how the tablet is set up as ArtRage doesn't have specific settings to turn these on and off. Default settings should work, but if you're having a problem, I'd recommend temporarily closing antivirus / anti-spyware applications, then removing entirely the tablet driver, restarting the machine and installing the latest driver from Wacom's website fresh. If prompted to remove custom profiles and settings when you uninstall the tablet driver, do so as this should make sure you don't have any unexpected settings in your tablet software.
Just in case, you can also reset ArtRage to its default settings by holding down the spacebar key when you start ArtRage. You'll know this has worked if ArtRage attempts to check for updates.
I'd advise leaving the no_ink.inf file in the resources folder, it won't make any difference under Windows XP, although it can help if you may have installed Microsoft's Ink Services at some point. I definitely wouldn't do a repair install at this point as I suspect the problem will be local to the tablet settings rather than something bigger.
I hope that helps!