I don't think this is really a bug, but ....
I just downloaded and installed CCleaner Free and ran the registry cleaner. Actually, I ran it twice until it said there were no more issues. I was impressed with the speed of the analyze and clean operations.
Just to check, I then ran [brand-X]. It found over 1000 issues. I'm just wondering why.
I would much prefer to use CCleaner because of the speed, but if it doesn't do the job, I'll use [brand-X] despite it's slowness.