It's more complicated than it needs to be - I think if you go into his profile, there are switches there. You should also be able to access your Ignore list in your User CP and add his name manually. Been a while since I've done it.
I don't suppose you fancy helping a fellow CM old timer? Do you know what the settings should be for a "realistic" gaming experience? It's not particularly clear in the options screen and I can't find a search option on the forum!