My upgrade on one of my machines for Picasa did not go well. As you can see below Picasa seems to have dropped all of the thumbnails on the upgrade. I posted to the Picasa help area - Upgrade from 3.8 to 3.9 thumbnails disappeared for all +30K photos (of course you can't upload a picture to Picasa help area), so I figured I blog about the issue and included some screenshots. You can see (Image 1) the grey dots that represent where the images should be in Picasa. Image 1 - Picasa lost ll thumbnail preview on images after upgrade -all you can see id icons Randomly the images are being rebuilt (Image 2), but for the number of images and faces I have in Picasa it will take several days to rebuild them all. Image 2 - Randomly the image thumbnails are being rebuilt I really like using Picasa as an image management tool. It really does seem like the best photo management tool out there. I have over the years compared it with other pay, free, and open source solutions.