i find that repairing permissions often fixes acrobat wonkiness. and trashing preferences is a good thing to try. as is running diskwarrior.
recently, i also have had to remove a new javascript but i cannot leave it in because it conflicts with the 'Crop Tool;' have you just added a plugin or something that might have changed how acrobat works?
you can try this forum
adobe acrobat mac user forum
the forum describes two big fixes for acrobat wonkiness: switching the chinese languages and nixing a word plugin -- which i mention to give you something to start a forum search.
if you post there, give your os (9 or x) and your acrobat version (5.05 or 6) and the complete error message.
hope this helps.