Maiden Name

This post about a guy's dealings with Visa brought up an interesting point. [For those to lazy to read it, it deals with a guy confusing the Visa operator about his mother's maiden name]
Anyway, this got me to thinking what about those who mother's don't have maiden names? Or if your parents are gay, you will either have two mothers or no mother and this will really screw up the system.
[sarcasm]This is so far the only convincing argument I have found that would make any kind of sense in banning gay couples from having children[/sarcasm]