As you quite rightly say, there are other people experiencing the same problem, and I'm sure it's something the development team are aware of, and will sort out eventually without the user needing to take an excursion into the registry.
If it's any help, I have never used the update feature, preferring to manually download the latest version from the following link, and with CCleaner closed down, do an offline install.
CCleaner: (File Hippo)
Assuming CCleaner downloads and installs without any problems for you this way, I would suggest doing that until the update problem has been resolved.
Hope that helps, and thanks for posting back.