A few years ago, I did a sales thread here on the boards. Had a fairly good amount of sales. For some reason though, Paypal was kicking back the payments ... they weren't allowing me to keep the money, they were automatically refunding the buyers. It wasn't like I was new either, I had been using PP to buy/sell for years. I called a couple of times and got the same answer "Yeah, we know what's happening, and why. But we can't tell you. We suggest you use checks/money orders." (One of the buyers even called PP and they told him the same thing.) Man, I felt like Cersei walking naked thru the streets ... so shamed. The weird part about it though, was some seller's payments went thru. (for roughly the same amounts)
Because I felt responsible (even though I did nothing wrong), I shipped the books out and asked the buyers to send the checks/MOs when they receive them. Luckily, there were no problems.
I've never done another sales thread. Don't need the hassle.