Regarding your first question, can you verify that your screen is at an optimal brightness and resolution? Then, check that NVDA's Screen Curtain feature is off. The other thing would be to check if the text is actually plainly visible on screen, in that it's not being cut off at one side or something like that. When did you last change your LION settings? You said you uninstalled the add-on but reinstalled it and restored your configuration. Might that mean that a setting is hampering its ability to perform OCR? Finally, what is the window size that you're trying to OCR? Is it tiled or taking up the entire screen? Perhaps making the windoe full screen will aid OCR.