When I installed the 64-bit v5.33.6162, the installer told me I had to reboot for the update. I found this extremely odd and questionable at the time since I've never been asked to reboot after a CCleaner update before...
I've updated to the latest version and can confirm that I have/had the 64-bit version, but what assurance do we have that this was solely impacting the 64-bit version?