Spell text is contradictory between the two. DM makes a call and runs with it.
Feeblemind specifies that the subject remains that way until a "heal, limited wish, miracle, or wish" is used, which pretty much precludes other solutions.
However, Feeblemind, the spell, fits all the requirements for a caster level check from Break Enchantment to fix it up.
DM picks one to "win" and moves on.