This last Monday (yesterday), the same thing happened to me, My BR and eBay username and password were the same before this happened. Someone in Nigeria won close to $19,000 (yes, 19 grand) in cell phones and laptops. I was asleep while this was going on, and was awakened by a guy calling from the UK that I had won an auction from. Both the screenname and password were changed and I was locked out. I immediately shut down my paypal (which did have a different password, thank God).
I used eBay live help and they set everything straight pretty fast. I sent messages to all the sellers that I "won" auctions for, and one of them wanted me to pay anyways! Today, all the listings were gone, and it was as if I was never hacked. Luckily, eBay seems to be pretty understanding about this whole situation. Still a bit unnerving though.