A friend of mine has suffered a similar situation.

He suffered a series of vindictive low ratings(DSR) and had a large sum of Paypal money frozen for six months (Just in case there was a new claim made against him despite all sales being finalised.)

Dealing with Paypal is like dealing with the CIA and gets nowhere. Whenever you get emails they are contradictory and you speak with people in Asia, Ireland and Salt Lake city. Nothing is cohesive and basically you are scarred for life.

If you start a claim through the financial industry ombudsman any funds in your account will be frozen until the case is closed and any income you may get in that time is also at risk.

It could be that despite getting positive feedback if you did not keep an eye on the anonymous DSR scores somebody could be leaving vindictive low DSR (my friend got 65 1 and 2 scores from one person for multiple items in 2 transactions.) That resulted in his account having very low selling limits placed on it and eventually he gave up on Ebay.

Once you are marked it seems to be impossible to get away from it, and Ebay / paypal say it is good to keep it anonymous.

As an example of how unbalanced things can be I had dealings with a chinese seller who has had 312 negatives this monthbut that is balanced out by 21,000 positives.

The point is though that they are receiving 10 negatives a day..So Ebay will continue to rake in the dollars because of sheer volume, and if someone is unlucky to have a couple of glitches they will hammer you.

That shows where the principles and ethics are.