Intermittently, books will open as a completely black screen. Once any book does this, all subsequent books behave the same way, even they have been previously read successfully (even the Cool Reader manual will render this way). The interface is still responsive (can get to options menu, table of contents, etc) but cannot read anything. Changing day/night mode, background and text colors has no effect. To recover, it is necessary to kill and restart the Cool Reader process. I am running Android 2.1 on a rooted Nook Simple Touch.
