I am still having this problem and it is making Pixa unusable. Here is some more info:
Sometimes when I go to quit Pixa it issues a warning message: "Pixa is importing files, are you sure you want to quit?" However, I've left it running overnight and any imports should have been completed. I also notice that the Pix Live Folders continually look like they are updating, but the file counts never change. i.e., in the "Images" Live Folder it says I've got 7 images, that number is replaced by a grey circle as if it is being updated, and then it redisplays the number 7 again.
I have attached the warning message mentioned about and a movie file of the Live Folders cycling through their updates. Your help is appreciated.