I don't think Stax is making two batchs of 009, one better for dealers and second worst for PJ.
There is one production line and I think all 009 are built with same quality.May be PJ is selling more 009 than other dealers and that is why issue is more popular on PJs headphones.
As far as I know PJ isn't a dealer, they are just a middleman broker who helps you buy the good from a Japanese retailer and have it shipped to them and then forwarded to you in the US without having to know Japanese, convert to yen, and deal with customs. There are other services that do this like Tenso and FromJapan but they don't seem to specialize as much like PJ does.
This is part of the reason why dealing with PJ is not easy after the fact; they skim a little off the top (and if I had to guess they don't make a whole lot) to provide freight forwarding; warrantying products with the manufacturer is likely not the same as they are not a retailer with a existing relationship with Stax as such.
Edited by Mr.Sneis - 7/15/14 at 3:02pm