Have a look at this thread on the .com boards:
http://community.ebay.com/t5/Selling/Order-Canceled-by-Global-Shipping-Pitney-Bowes/m-p/23979261#U23...
I have seen other similar threads on the .com boards and they were all created in the last few days. It seems that the GSP folks have started returning items to sellers for whatever reason. And if my understanding is correct, they seem to be refunding the buyer from the seller's funds, including the GSP portion of the buyer's payment.
I can't find any announcement or anything else from eBay (no, really!) regarding what appears to be a major change. It looks to me like the GSP folks could be starting to return items to sellers instead of selling them through their eBay liquidator. And what's with deducting the GSP portion of the payment from the seller's funds? Is that temporary (like the "hold" that is put on the seller's funds whenever a buyer of a GSP item opens a dispute)? Is this some kind of "test" or are we looking at a permanent change? It would be nice to get some kind of information from eBay because looking at the .com boards, everyone seems totally confused by this.