How many seconds before the deadline the auction ends? I just bid a player 5 seconds before the auction ended and it was not computed!
It ends right on the deadline on server time. Usually in cases like this, it ends up being related to the page you're in no longer being synchronized with the server clock (i.e., if you hit the back button on your browser in a tab with BB open, it may show an incorrect server time). In the few times I've actively been trying to bid on someone important enough to notice, I've learned that the best way to refresh the bid on a player is from the player page, in the dropdown that opens under "Player History" select "Overview" and that will refresh the page. I wouldn't hit the refresh button/F5 because that may post a bid, though that probably wouldn't actually matter if you haven't modified the bid price since your last bid.