I encountered the same problem using XP SP3. I reloaded CC 4.08 and that one works fine for SHUTDOWN. Then reloaded 4.09 and it failed. I am going back for now to 4.08 as i use this feature all the time.
I love the option of "shutdown after clean" but could you add the option of "restart after clean".
FYI: the option of "shutdown after clean" is found by right clicking the minimized icon when running using the command line option of "/auto."