I think I've found a bug ?
If I make it read all my journals, then go in and edit the settings (cos I don't want something to show), then click Read All Logs button again, it just blanks the content as expected, moves the green status bar across the bottom of the window, and then doesn't show anything once it's completed. I have to completely close the app and reopen it, then press the Read All Logs button to see the view as per the configured settings.
In other news, I'm absolutely loving this app, it's something that I run all the time now. It's a shame there's no Records API in EDSM, cos it'd be cool if you could have criteria that checked against the known records for a body (ie you just found a star larger than the record, or you just found the smallest planet).