I use metacreator and it fills in all the numbers from the RAW. On the Core rules character sheet at the back there is a section for a multicast score. Where is this info from? Is it a legacy from 4th. To my understanding multicasting is for spell mastery only and uses a different calculation from this one doesnt it? Is there an errata I have overlooked or an eldritch passge concealed except on the autumn exquinox I have not discovered. OR, am a complete retard who has totally misunderstood.
The current beta has already removed the multi-casting line from the printed character sheet. You can correct the problem in your version of the software in one of two ways:
Edit Formulae.txt in the Metacreator source directory and remove the offending lines.
Create a CustomFormulae.txt file and include whatever text you want to appear in that location. See "character sheet customization" in the help index for Ars Magica 5 for more details and an example.