"Mom" contact changes to "Mom Mom"

On my iPhone I have the contact for my mother simply entered as "Mom" for the first name. However, at some point, and I have trouble catching exactly when, it will change from "Mom" to "Mom Mom". With a "Mom" in the first name and a "Mom" in the last name. I manually change it and it eventually goes back to "Mom Mom" after I've synced it with my computer. I say eventually because it doesn't always change after I sync, only sometimes; but sure enough, given enough syncs over time, it will change back.

I've checked both the contact info on my iPhone address book and the contact info on my computer's address book, and they are the same. But somehow "Mom Mom" will find its way back onto my iPhone and my address book.

I've noticed that when I start typing in my mother's email address in the Mail client, the auto-fill suggestion will come up as "Mom Mom". So my question is...how is this auto-fill information stored? Is it separate from the Address Book? Is it overwriting my address book info? How do I change it?
By the way, I do not have this problem at all with my "Dad" contact.

I posted this question a while ago and it went unresolved. I'm STILL having this problem and I can't get an answer, even when I call Apple.