Yes this is one of the huge flaws with
ebay's new feedback rules, so that's why I have stopped selling altogether and shut my store down. I guess your only option to avoid this scenario is one of two ways:
1) Make your opening bid and buy it now one in the same, and make it one of those auctions where they have to pay immediately with Paypal to close it out. That way if someone really wants an item you have, they have to pay for on the spot and if they dont the listing stays up until someone does.
2) Open a store with a fixed price listing format (no bidding or auction format) and the price you put on there is the buy price. Again do the option where immediate payment is required.
There are downsides to doing this including having higher listing fees due to the higher prices you may have to set, fees from using Buy It Now, fees if you open a store, and finally you may "leave money on the table" if you set your buy price too low. But if you are seeing alot of non paying activity then these small inconviences may outweigh what you have to deal with now.