[Phanx]

Replace the contents of the addon's Lua file with this:

local ignoreZones = {
	[806] = true, -- The Jade Forest
	[809] = true, -- Kun-Lai Summit
}

local f = CreateFrame("Frame")
f:RegisterEvent("UI_ERROR_MESSAGE")
f:SetScript("OnEvent", function(self, event, message)
	if (message == SPELL_FAILED_NOT_MOUNTED or message == ERR_TAXIPLAYERALREADYMOUNTED)
	and not ignoreZones[GetCurrentMapAreaID()]
	and (GetCVarBool("autoDismountFlying") or not IsFlying())
	then
		Dismount()
	end
end)

If you want to add more zones, you can find a list of Map IDs here:
http://www.wowpedia.org/MapID