I use Bridge as my browser. When I browse through a folder for the first time, thumbnails come up normally and so does the full screen preview. However the next time I reboot the computer, although thumbnails re-appear quickly, previews come up very blurred and do not sharpen unless I delete the cache, either for the individual file alone or for the whole folder. Then it all works well again until the next time. This is an ongoing problem. Any ideas please?