Last night, I deleted about 30,000 little files in my WINNT\Temp folder. These were all about 1kb in size and created by my HP software just like the posters you found in the HP forum.
After I deleted them, I defragged and turned off the computer.
This morning, the folder is still empty, but cCleaner still takes about a lot longer than it should for analyzing an almost completely clean computer. As you can see by the screen shot, it took almost 6 minutes to analyze.
So although fixing the HP problem helped, I think there is still something wrong with my installation.
Any thoughts?