Just remember that hitting the UPDATE PRICES button has nothing to do with AS sending your snipe--it will go through, regardless.
The purpose of the update button is for you to see the most current price. Naturally AS cannot continuously update every auction for thousands of snipers; that would take considerably huge and wasteful resources. They update the auction once a day until the final 24 hours, when they check it after 12 hours and then numerous times in the final 12 hours.