... So very frustrating!
I bought a PRS-600 as a birthday gift for my wife. SONY advertised a key feature of the reader (compared to, say, the Kindle) is that you can read library books of various formats. That was the main attraction in our case.
Now, the fact that SONY readers' firmware (all models?) has a defect that precludes one from being able to read both DRM-protected EPUB and PDF files at the same time (note: roughly 1/2 and 1/2 of our library's books are mixed between these 2 formats) is incredibly frustrating.
But the fact that SONY's advice to disappointed customers (trying to figure out why they get a "Protected Page" error when trying to open a library book) is to ignore the problem ... now, that's even more maddening.
Of course, first you have to google around to figure out WHY you're getting these darn error messages. SONY doesn't actually TELL you that its firmware is defective. You have to spend several hours of additional frustration figuring that out too.
Finally, you'll come across this little gem of a link:
http://www.kb.sony.com/selfservice/d...nalId=C1008686
Along the path to knowledge, you may come across several well-intended folks suggesting it's a DRM issue or an Adobe Digital Edition problem. Rest assured, it's not. Other brand readers do NOT have this problem (now we also have a nook in our household and I've read other brands don't suffer from this - ignoring Kindle which can't read library books anyhow).
Simply put, SONY knows about the problem and as recently as yesterday, sent me the customer support link above - i.e., same link as has been around for a while now.
In effect, SONY's advice is: if hurts to exhale, then we suggest you don't exhale.
Unless you have no interest (now or in the future) in using your SONY e-reader to read library e-books, then I strongly suggest you NOT buy a SONY reader product. You WILL be frustrated and, yes, SONY will do nothing about it except tell you to refrain from using it the way it was advertised to be used.