I recently purchased a Sony D25-s with Radio Shack wallwart from curt222 (Dan Curto). I figured I was better off buying a "tested" model from a Head-Fi'er than ordering one from Silicon Salvage, plus the deal would save me a trip to RS and the expense of a wallwart.
Everything went smoothly, I paid with PayPal, he sent it out quickly and a few days later I had my new toy. Only problem was the D25-s wouldn't work. It would turn on, start spinning the disk and shut off a few seconds later.
I informed Dan via e-mail. He was very understanding. Based on various Head-Fi posts about the sensitivity of the D25-s to voltage, we both suspected the wallwart. Without prompting, Dan offered to help me out with the purchase of a new wallwart or, if that didn't work, to refund my money.
I tried a new wallwart with rock-solid voltage (RS 1667) but had the same problem. Dan immediately refunded my full payment via PayPal and I sent the unit back to him. No fuss, no muss, no hassles. I was just out the return postage, which was totally fair as far as I was concerned. I kept my new RS wallwart and ordered another D-25s from Silicon Salvage.
Great person to deal with, went above and beyond the call of duty on this transaction. As they say on eBay, A+++++++++++!