Which it how it's supposed to be, so don't sweat. ^_^ Unless it's French, which means it would be.... I think "Go". But it's not, so.. Gow. XD
I've actually never heard Bart's (Xenogears) last name said out loud, so I don't know if it's "fa - dih - muh" or "fa - tee - muh"... I'm going with the first one though, because that's how my mom and sis say it.