I have only done it a couple of times but its annoying when you are trying to pay down debt.

I paid one of my credit cards 2 days too early so now I am also coughing up a min payment for the card in addition to what I already paid on it. Not a huge deal, but annoying. Especially annoying is the fact that if I hadn't checked something else on the website I would have never known.

Of course, the other money issue annoying me at the moment is an uncashed check. I was refunding my firm the unused portion of petty cash for my business trip and its now 2 months later and they still haven't cashed it. Guess I am going to have to ask if they lost it.