It was during ebay’s scheduled maintenance:
http://www2.ebay.com/aw/announce.shtml
. . . but, AS should have placed the snipe before that.
You could try clicking on “View Confirmation” button (next to the snipe), and if no further suggestions, file a support request:
http://support.auctionsniper.com/
Sounds like AS goofed, so be sure to file for some free snipes:
http://www.auctionsniper.com/freeSnipes.aspx