[Xrystal]

Oh another set of functions in that file that might shed some useful information for you.

function SpellButton_OnDrag(self) 
	local slot, slotType = SpellBook_GetSpellBookSlot(self);
	if (not slot or slot > MAX_SPELLS or not _G[self:GetName().."IconTexture"]:IsShown() or (slotType == "FUTURESPELL")) then
		return;
	end
	self:SetChecked(0);
	PickupSpellBookItem(slot, SpellBookFrame.bookType);
end

And some other functions that may have changed:

local temp, texture, offset, numSlots = GetSpellTabInfo(SpellBookFrame.selectedSkillLine);