Based on your other thread you also seem to be using Vampire Embrace. AFAIK, you need to be pretty careful with the load order of vampire mods, including Scripted Spells. So, firstly give mlox (linked in john.moonsugar's signature) a whirl.
If that doesn't clear things up then please report with your mod list (ideally from mlox as that shows things in load order, or from the bottom of your morrowind.ini) and the contents of your warnings.txt file (that'll be in the same directory as morrowind.exe).