If you copy and paste the code below into a Graal level and run the level you will see it tells you if a mouse button is pressed down. Now left click and hold. Move the cursor off-screen and let go. See how it says the mouse button is not down? Now do the same with with right mouse button. When you let go off screen the Graal.exe still thinks the mouse is being pressed. This is a very big bug for anyone who uses the right click for anything in their scripts.
NPC Code:
if(timeout||created){
if(mousebuttons>0){
message Mouse is down!;
}else{message Mouse is not down!;}
timeout=.05;
}