Nope. Someone flamed you in feedback .. Only eBay can do it. They will only do it if you both agree under adjudication .. or it is swearword or particularly offensive.
The feedback function would be pretty useless if that was the case. Everyone would have 100% positive. You can however change your feedback on some other trader, once I believe.
There is the occasional idiot on all auction sites so it should not be considered bad if they have slightly less than 100% positive. I consider 98%+ trustworthy but investigate further if below that.
What really annoys me is they can say what they want and leave negative feedback but you are only allowed to leave possitive feedback on a buyer even if they dont pay!
Agree with boxtops but you can also bar that buyer from buying from you. I'd get in touch with them and try to sort the prob...it's only them that can reverse it.