Our GM is digging his heels in on this one, would love to hear your thoughts!
Break Enchantment says "This spell frees victims from enchantments, transmutations, and curses. Break enchantment can reverse even an instantaneous effect. For each such effect, you make a caster level check (1d20 + caster level, maximum +15) against a DC of 11 + caster level of the effect. Success means that the creature is free of the spell, curse, or effect." and "If the spell is one that cannot be dispelled by dispel magic or stone to flesh, break enchantment works only if that spell is 5th level or lower."
Feeblemind is an Instanteous Enchantment Spell and qualifies under all this.
However Feeblemind's text says "The subject remains in this state until a **heal, limited wish, miracle, or wish** spell is used to cancel the effect of the feeblemind." - which the GM is holding fast on, saying that if Break Enchantment was supposed to work then it would be on this short list.
I know it's a small thing but any clarifications or errata would help the player affected. Thanks!
Feeblemind has specific langauge so your GM is correct. If it said in addition to break enchantment or in addition to normal means then break enchantment would work also.
I'd say this is a case of where specific beats general. Feeblemind specifically states the parameters for curing it; heal, wish/limited wish, and miracle. Short of that, nothing else. I'd say the GM is right on this.