Have you installed a Wacom tablet or something similar?
YES! But it was ok before, even with the drivers installed.
(This happens with the touchpad and magic mouse too).
I've seen a number of people with issues on these forums with keyframes not letting go when you let go with the mouse and other odd things - almost always when a Wacom tablet has been installed. The problem continues even if the tablet is unplugged.
I wonder if your issue is related.
I uninstalled the driver and everything is smooth again! I've never had this problem before with this same Wacom tablet (maybe is too old 2010?) and AE. Now i guess i need to figure out what to do. Do you know, per chance, if this wacom tablets were older models not being supported by the wacom team anymore? (like mine). If thats the problem i guess i will have to get a new one.
Anyway, THANK YOU VERY MUCH!