I haven't posted here before. Found the site when my reader library wouldn't launch (but still shows up as running in my task manager). I tried all 6 or so solutions tossed around in this thread. Four hours and twenty reboots later, nothing was working and I was ready to pull my hair out.
Today I called Sony Support, expecting a three hour ordeal with different departments/agents playing hot potato with my issue. Surprisingly, the agent took charge of my computer through remote access and the problem was resolved in a matter of fifteen minutes. She uninstalled the software and installed it again and that seemed to solve the problem. As far as I can tell, the only thing she did differently than me was that she used a different installer package than the one I got from the website. Here is the link:
ftp://download.sony.com/US/reader/re...library_31.exe
Hope this helps. If it doesn't, it seems like Sony Support has got a good enough handle on the situation that they can help you out.