I got a quick reply from Support. It's not very reassuring to me. They say the issue with Ebay has been resolved, but they admit that the problem was out of their hands. If it is an Ebay problem, AS probably wouldn't be able to verify that any problems were fixed. And, as AS users, we certainly can't verify that the problems were fixed. Obviously, the problem persists for some people. I don't think AS knows how to fix it.
From Support:
I‘m sincerely sorry your bid on this item was unable to be placed successfully. The failure of this snipe was actually caused by a sign-in issue on eBay‘s end, which has since been resolved. We sign into eBay approximately 3 minutes before a snipe is scheduled to be placed, however, during this period, eBay was not accepting our sign-in requests in a timely manner, so we could not place this bid on your behalf.
When we are unable to sign-in to eBay using the log-in information stored within your account, we display the "WARNING - Your stored username or password might be incorrect!" as a reminder to update your eBay sign-in information in the Auction Sniper system. Since your log-in information is correct, even though this message is displayed under several of your active snipes, they should still be placed successfully.
Although this issue was beyond our control, for taking the time to report this problem, I have credited your account with 3 additional free snipes. Auction Sniper provides the most effective and reliable automated bidding service in the industry and, for that reason, we hope you continue to use our service.