This is very inconsistent behavior, but usually if I'm holding the right click button on my M1400's stylus and hovering the pen above the screen, the cursor becomes jumpy (dances around a bit) and unresponsive, and sometimes even clicks the screen before I actually touch the screen. As soon as I let go of the right click button it goes back to normal.
This makes it hard to accurately right click. Anyone know about this? My stylus hasn't been replaced since I got the unit >3 years ago, but I can't remember if I had this problem at the beginning.