In addition to posts #17 & 18, I have found out more. Knowing I almost never use Safari, & that it's History would never fill such a large (480kB) file, I figured the entries were all bookmarks. Since I had bookmarks imported from IE & Mozilla in Safari, I first decided to delete the Mozilla bookmarks. Then I rechecked Safari-Internet History box & ran CCleaner. The CCxx.tmp reoccured, as expected, but it was much smaller (290kB), as I anticipated, since now Safari had fewer bookmarks in it. I then deleted the imported IE bookmarks & reran CCleaner. Again CCxx.tmp was found, but now it was even smaller (13kB). Opening CCxx.tmp, with WordPad, I can see it's made up of the remaining Safari (~25) bookmarks. CCleaner will analyze & find, but will never delete CCxx.tmp, until I uncheck the Safari-Internet History box. Hope this helps too.