1. Enter fullscreen mode in pre-12 NotEye version
2. Do something that has a (more) prompt, like talking to an NPC with multiple lines of dialog.

Now a small yellow highlight follows the mouse cursor around. This is a little weird but not a problem. The problem occurs when you move the cursor out of the top or bottom of the ADOM play area -- the highlight leaves a trail wherever it goes. Check the attachment to see what I mean. The only way to get rid of the trail as far as I can tell is to leave fullscreen mode and re-enter it.