Since a few days now I am running my download manager sandboxed (I use Windows 7 64bit). I feel more safe checking first within a sandboxed environment if the extracted downloads are really what the “wrappings” promised to be… without any extras that may harm hard- or software 
Usually when the downloads are ready the download manager puts the PC into hibernation mode. So in order to grant sandboxed applications hibernation privileges I added the following to the exception list:
C:\Windows\System32\rundll32.exe
C:\Windows\System32\powrprof.dll
C:\hiberfile.sys
Unfortunately this did not work. I expect that more exceptions may be necessary. Does anyone have any ideas…?
…and “No” - I don’t want to start a discussion about the usefulness of a sandbox with granted privileges on parts of the operating system :-X