How to disable long touch = click on MacBook Air touchpad? If I leave my mouse in one spot for several seconds with my finger on the touch pad, it interprets it as a downclick.  So if I hover over a file while thinking about something and then move my cursor, it will try to drag the file, if I hover over text and then move the cursor it will select text, and so on.

I have gone into the System Settings and unchecked "Tap to Click" already, but that doesn't seem to do it. Is there another way to disable this feature?
Did you put more than one finger on your pad ? Precisely, did you put exactly three fingers ? That may be your problem, and therefore your solution. In the preference menu, you can disable the "Three finger drag".