Mike
You're quite right that the word sex, when it's used to mean "gender", is not something we'd decline a site for. Although having said that, if it's about choosing your baby's sex/gender then we would, but clearly that doesn't apply to your customer's site.
Can you PM me the site URL so I can double check everything?
On the Amazon link thing, Jon's already covered that and there shouldn't be declines so I'll try to make sure that's not happening again.
Amin