One incident in 15 years, and you no longer trust the application... How's your personal relationships? Few and far between I bet.
That ridiculous statement aside; I think you'll find there will be a legitimate reason beyond AuctionSniper's control for you not winning the auction.
Experienced this myself for the first time a couple of weeks ago. Turns out sellers can pre-block certain aspects for a buyer, such as unresolved disputes, negative feedback, your location and a number of other things. They can also block you completely, but only if they know your name / ID first. However, they cannot block sniping. What you have most likely encountered is a seller who has blocked you completely (after the fact), if they suspected you have used a snipe on a previous auction and they simply disagree with it. Ask yourself; have you bought something from them before? Did you use a snipe to buy it? Most likely, I think.
In fact eBay themselves claim not to have a mechanism in place that can block sniping, nor do they wish to, as it actually works for the seller, and thus works for eBay.
You can read more via the link provided, however here is the meat of the argument:
There is currently no way a seller can block a Zero feedback bidder who snipes.
Under current eBay rules, a seller can pre-set blocks on any bidder who has a feedback score of -1 or less or who has a certain number of unpaid item strikes, etc. Aside from very specific rules and parameters, a seller cannot pre-block other bidders, therefore all bidders who are not pre-blocked by parameters set by the seller can bid.
If you jump in and bid early the seller will have plenty of time to scrutinize you and block your bids if he feels threatened by you. If you bid only as a sniper, no seller can block you merely because he thinks he might not like to deal with you.
http://www.ebay.com.au/gds/Sni...0000002606004/g.html
Anyway, happy sniping.
Painfull