Anyone else running into this problem?

I know others have reported the problem of the list not showing up on launch and that it's necessary to select one of the sort buttons on top in order to have them display.

However, I've been recently running into a problem where I go to select a category and the program just freezes and won't respond to anything that I do. I've tried deleting notes. I've even tried deleting the program and reinstalling and then restoring my backed up db file and the same thing continues to happen...

I've also tried deleting individual notes, in case there were too many, nothing. I also tried deleting a category...nothing. I even deleted every note and tried adding a new one, and when I went to add a category, it locked up. I then started over from scratch, removed my old db file and uninstalled, then reinstalled the program. When I went to try and change the category of the default item, it locked up.

I'm thinking there must be a corrupted file, but I'm unsure how to get to it and delete it. Does anyone know how to tell which file in which directory is associated with a particular program?