Me too. I almost always snipe anything I'm bidding on. Only twice have I ended up not being able to submit to the bid, once was because it started responding much too slow, another I underestimated the time needed.
Most of the rest of the time, here lately, I just completely forget about the auction until mere hours after it ends. Then I'm pretty annoyed.
At the same time, I also keep asking questions and the seller keeps not responding (multiple times, get no response more often than not) and I'm not gonna bid on something with a seller like that, even if I don't really need to know whatever I asked. The most annoying is when they have 'just ask any questions!' in the auction, yet they don't respond.