The 0.8.14 version is used like a standard iRex app, so it is designed to be invoked from the contentlister by selecting a filetype it is bound too in the registry.
The older 0.8.04 version can be added to the registry, but can also be invoked stand-alone from the Programs directory. This is the version that works like FBReader on other computers, with an internal library and book selection via a file navigation window. If you want to switch to version 0.8.04, first uninstall 0.8.14 - see
FBReader uninstaller. If an uninstaller came with 0.8.14, then that should work instead of this one.