This behavior has been reported when the 'Use shortcut menus in drawing area' checkbox is unchecked. To avoid the behavior, make sure that checkbox is checked. If you wish to use the right-click primarily as ENTER/last command, click the 'Right-click customization' button, check the box for 'Time-sensitive right-click', and set the time to a higher number (2000, for example). With that time setting, a shortcut menu would only come up after holding the right-click for 2 seconds.
... Other than that soloution above as that does work for me but it limits other things. I would have thought this would be something that would be a priority to fix. There are already 3 people at my work who will not use 2012 for this reason.
This forum is not the spot to ask for fixes: if you are on subscription, try harassing them there about it and hope a few hundred other users join in with the exact need.
If it is in the works, sign up for beta testing and get the inside scoop on future dealings and help influence future development.
I have been having this issue for a few weeks now. Thought I was going crazy. Happy to say I can delay that a bit longer. Problem now is something has happened to one of my files. Annotative blocks with text. They have all disappeared. They are still there, but cannot be seen. Obviously some system variable has been turned off. Any thoughts?
Opened the file in 2010 and in 2010 and 2012 on a different computer. Nothing.
After a days work I don't want to go back to the overnight backup.
Why can't these things happen at the start of the day.
My randomness turned off ATTDIS.
Generally I get a dialogue box so they are obvious.
This time was command line and I did not notice the change.
Beware of mystery random commands
I've been getting the right click problem too, after much googling I've found there's a new variable in 2012 for 'pickdrag', when this is set to '2' I get the right click problem, I've now set it to '0' which is the original setting for previous releases of Autocad and right click so far seems to be back to normal with no frustrating random commands.