9,480 files?! I would definitely agree that's too many files in the Profile folder. I think you need have a look manually to identify some sort of pattern to the madness of the amount of excessive files. Even if you have multiple Firefox profiles, that number sounds high. A normal profile should have somewhere around 58 items (that's including folders). That number is from a Mac and freshly installed Firefox with 1 addon installed. For Windows & Linux, it should be 58 items as well or very close to it. Your cookies will be contained in a single compressed file called cookies.sqlite & it shouldn't be 500 MB (half a gig). The problem could be a single file that's getting repeatedly created over and over again. But you need to take a look to find out what it is. Maybe try looking in the Crashes or Minidumps folders in the profile?