Yeah, thats an interesting twist. I believe it says if its lost or stolen, but I don't know what they'll do if you just get screwed on a purchase. I wouldn't think it would be hard for them to issue a new card and re-imburse you for the amount, but its never safe to assume anything when it comes to money, or anything for that matter I guess.
Let me know what they tell you about it, as I have one myself, but refrain from using it online if possible. The only times I did use it were for a place like Newegg that I knew I could trust.
Wow that was fast. Good to know though.