Don't know if this is v2.25 specific as I've only just discovered it but have found the portable version is finding Flash Player files that the installable version doesn't pick up for some reason. The files the portable version is picking up are:
C:\Documents and Settings\user\Application Data\Macromedia\Flash Player\#SharedObjects\EB8VEWFA\mail.google.com\wakeup.sol
C:\Documents and Settings\user\Application Data\Macromedia\Flash Player\macromedia.com\support\flashplayer\sys\#mail.google.com\settings.sol
This is on XPHome, both versions are 2.25, neither have any exclusions or inclusions set
Well after much head scratching and trial and error deletions of sections of CCleaner.ini the penny finally dropped dropped when deleting the cookies to keep section of the ini cured the problem. Of course, .sol files are used for flash cookies aren't they, it's the Gmail Flash cookies and I have the Gmail cookie set to keep.