I've always pronounced it like mee-buh, simply because I'm deslyxic and I tend to pronounce things wrong. But a friend of mine said it should be pronounced mib-buh. I don't really care, though, because I usually don't say Mibba out loud. XD
@ IchBinDinosaur Thanks for mentioning me, sis -.-
I pronounce it like Mee-buh. It rolls off my tongue a lot easier than pronouncing it like Mih-buh. But if it is pronounced like Mih-buh, I'm just gonna feel really stupid