I updated to Mac OX 10.8.2 and I am still having the same problem.
If I use the cursor to move an item it duplicates it instead. If I go to EDIT > UNDO it even says "undo duplicate."
Keys are not stuck, as I still need to push option-click in order to duplicate/clone things in Photoshop.
Is there some way to remap or reset how flash is treating the regular selection cursor tool? It is being treated like a duplication tool right now and it's making flash completely unusable!!!!
Any advice would be appreciated.