I believe no matter how good of a seller one is the law of averages will always catch up! You can do every thing by the book and add a twist of great customer service to it and still one day, low and behold, you will open up your eBay account and your score has dropped a number, you click into your feedback board to see some A-Hole has left you a negative that you totally did not deserve (don't get me wrong ,I'm not anti -neg, if you deserve it for doing out right bad biz , then by all means you should get a neg) But, when you have hundreds of satisfied customers and your really on your game and have provided a service to the best of your ability with a big smile and you get a negative because of some devious idiot! Well to say the least it's completely unfair and eBay don't seem to really care so your STUCK with a negative on the great wall thats your reputation on eBay...

      So... what to do now? the answer is simple....MOVE ON! If you have a good product people will understand this Law of Average (Average Jackasses) and continue to buy from you... If anything your overall feedback is what really counts! People will often leave negatives because they are just out right scam artist, they will tell you "I want a refund, I don't want to have to leave you a negative" YEA RIGHT!
This is called extortion and should always be reported to eBay.

   Bottom line is if you sell on eBay for long enough, YOU WILL GET A NEGATIVE FEEDBACK, I don't care if your selling a million dollar block of gold for 25 cents! Some jag off is gonna leave you a negative, count on it, when you get it don't let it get you down, move on and know at least you got it out the way and most of your customers are going to be looking at the big picture not some jag offs little sabotage pop shot!