Offensive Mage Trusts not Casting Magic

So quite a few of my Caster Trusts won't cast spells any more.

Robel-Akbel was one of my favorites and now he sits with 100% MP because he refuses to cast anything. He doesn't have hate, or anything like that. What's going on!? Am I the only one that's having this problem?

It's an issue that happens with any mages that select their spells based on elemental weakness when facing mobs Very Tough or higher.