Ahh yes :\ Pixologic is right though that's not a ZBrush problem, occasionally the tablet service just fails to load and won't work in any app. ZBrush spits out errors while photoshop simply disables all tablet brush options as it assumes you dont have a tablet.
I have an intuos 3 and its a bit buggy at times, I usually have to reinstall the drivers every couple of weeks because of a conflict with ZBrush (which pixologic blame on windows 7). I was considering buying an intuos 4 to fix this, but they use the same drivers so meh. I've also noticed since 2010 they've only released RC…