Sometimes you just have to put an end to things that don't work. I found myself in that position today with Sony. Of all the retailers that Smashwords distributes to, they have been the most flakey. They seemingly ignored several updates, then they had two accounts for me. The latest was that they removed 4 of my 5 books. All the problems with the others retailers have been quickly and easily fixed with an email to Smashwords, but Sony hasn't been easy in any respect. Baker-Taylor's Blio is snails pace slow, but they have yet to mess anything up. Kobo lost two covers, but that was quickly fixed. Sony has just had far to many issues and it hasn't been a money maker so there is no reason to continue.
As a company, Sony makes some good products. I'm on my third Sony TV (because I've upgraded, not because I have had any problems). I've had good luck with most everything of theirs I've tried, but distributing to them as a retailer has been rough and I don't need to be worrying about what will happen next. So, it is time to part ways. If anyone reading this has a Sony ereader, please use Smashwords from now on. If you ask nicely, I may even give you a coupon for a free ebook.
Best of luck to the rest of you using Sony.