The problem the Library Launcher is still running. If you have a startup manager program use that and look for "eBook Library Launcher.exe". If not you can get something like CCleaner (
www.ccleaner.com) for free and uninstall or disable it. Or you could try trashing the .exe directly, mine is located in c:\program files\sony\reader\data\bin\launcher\ebook library launcher.exe.
hope this helps!