If you run OD as an administrator under Windows 8, you can add a SysStats docklet. If you don't run as admin, OD crashes as soon as you select SysStats from the docklet list.
Even if you run OD as admin, context-clicking the SysStats docklet on the dock and selecting Load (to load a meter theme/icon) will crash OD. It's 100% repeatable on my system.
I haven't tried completely disabling UAC, but I shouldn't have to, I don't think.
PS - sorry for not responding sooner, but apparently "Subscribe to this post" doesn't mean the same thing as "Email me when someone replies".