Finally, I think I found out what is causing erratic pen behavior with Intuos. It seems if you keep 2 Intous tablets next to each other, it somehow interferes the pen's ability to track smoothly on either tablet. I used to have problem of automatic right clicking when I hover the pen near the dock areas (which makes the table impossible to use as it just automatically keep opening the apps in the dock as I hover the pen over the dock area). When I put several inches of distance between Intuos tablets, this behavior has stopped. Now I can use Intuos without a problem. I did not see any warning about the interference on Wacom's manual, though. Anyone who has 2 Intuos tablets has experienced this issue?