Hero Spell not showing up when researched

I'm trying to make the Cow King from d2 a hero. I've given him lightning enchantment and spell resistance, but the spell resistance skill doesn't show up in the researched skills list. However, it still works. I made sure the coordinates are right for the icon slot and made sure that an icon was set for research, normal, and turn off modes but the icon + information on the skill still don't show up. Is it because this was originally an item spell that it doesn't show, and is there any way I can fix this?

It is because it's an item ability with no provision for using an icon. You can fix it by making a dummy skill that has no effect but has an icon, and add it to the unit via trigger when he learns the real skill.