From the first reply this was heading way OT ... apologies to the OP.
It's the OS that is beta, ok? To test application compatibility in a beta OS, you need to install and test the programs that you normally use. If they work or they can be tweaked to work, then fine. If they won't install or run, then the OS and App developers have a chance to work to get things working smoothly.
Until the software has been tested on the OS, you don't know if it's incompatible or not.
If you check the link I posted earlier, you'll see that this problem has been happening since before Vista was released and may not be related to CCleaner.