I use CCleaner Professional on Windows 10. Searching the forum, I found this problem had occurred a few years ago, but the solution proposed then does not work now. Problem: After several hours of Firefox use, I think CCleaner is unblocking some cookies that SpywareBlaster has blocked. It is notable that the cookies unblocked each time proceed through SpywareBlaster's list alphabetically not randomly, and the alphabetic process continues over system shutdown/reboots. For example, on one day cookie Lop.com(25) gets unblocked and then the next day cookie Lop.com(26) gets unblocked. For me, this has been going on for months and I have eliminated many possible culprits, narrowing down, I think, to CCleaner. Please correct me if wrong. The old solution was to uncheck "Site Preferences" in Firefox's cleaning options. Well, that has never been checked in my installation. Nor is it checked for Firefox (or any other browser) in CCleaner. I am step-by-step disabling CCleaner's automatic executions to see if the problem goes away. Please let me know if there is a known solution. My instinct is that there is a range/boundary error somewhere, but that is just a guess.