metamorphasis + Spellbook = Trouble

I have a spellbook, in the spellbook is a spell based of stormcrowform and 1 based of bearform. they are kind of dummy spells though, i replace and stuff with trigs... it all works fine. now outside of the spellbook, my hero has an ability based off of metamorphasis. when he uses it, he has all the abilitys my old hero had (thats ok) but the thing is... his spellbook, is empty thats ok too.. but the prob is, when he goes normal again, its still empty. so how can i fix this?
note: spellbook is a hero ability

You can't fix it, I'm afraid... or at least I think you can't.
I had a custom hero with a non-hero-spellbook-ability, and a Metamorphosis based ultimate. The same problem occured.

Just a bug I suppose. ;)

well, I guess i could use the same trick with the meta that i used for the spellbook abilities. I check if the unit uses the ability and if he does, i move the hero to the side and replace it.