I also had this problem on 98SE using the latest version of CCleaner. I tried uninstalling and reverting to an older version and the problem remained.
I then noticed that I had the same problem with Control Panel/Add Remove Programmes
The Add remove list showed correctly in 3rd party utilities but the first item (Outlook Express) had no name, and showed as a blank item. I added a name, using TuneUp Utilities.
Opened Add Remove in control panel and under the first item were a number of blank lines. These relate to, I assume, uninstall entries that had been previously removed, the valid entries had simply scrolled off the bottom of the window.
I removed the blank lines by selecting each in turn and clicking Add/Remove. Windows claimed that this was an invalid entry and removed it. Repeated untill all the blank lined had gone.
Once the list displayed correctly I ran CCleaner and it worked perfectly.
I don't pretend to understand why Add/Remove list would affect CCleaner, but it does.
Scary.