Ever since a long time ago CCleaner is no longer effective in cleaning Adobe Flash Player LSO cookies for Firefox.
I have checked the Adobe Flash Player and all other Adobe products in the applications tab for cleaning. CCleaner shows that the flash cookies were cleaned underneath the details of deleted files, however once Firefox is started up again the LSO cookies appear again when I look at the settings manager ( http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager07.html'>http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager07.html ).
This is a very serious problem as the the cookies reappear after CCleaner shows that it was deleted.
The cookies stored shows a list of flash sites you have visited.
Try it your self. Just close Firefox and run CCleaner then go to the Adobe Flash Player settings page located at
( http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager07.html )
It will have a list of all the websites you visited in the box.
I suspect that it is a problem of either insufficient system privileges for CCleaner to delete the cookies, or a new Adobe anti-CCleaner code that repopulates the deleted cookies after deletion.
This bug needs to be fixed now because it has been a problem since 2.34 in August 2010.
See forum post
( http://forum.piriform.com/index.php?showtopic=29432 )
More information:
CCleaner version 3.06.1433
Windows 7 64bit and Vista 32bit
Firefox 4.0.1 ( Bug existed in previous versions too )