I have enabled all of the options under the systemUI menu (I personally don't recommend anyone to do this as well unless they are knowledgeable with working under CLI if things don't work out right).

The reboot button I have noticed that if N900 is still plugged into the microUSB port during the reboot cycle will cause the device to constantly reboot until the cable is unplugged.

My setup:
- Powered USB Hub (which has CA-101 connected to N900)
- Running linux host and at the time of issue N900 was running pc suite mode with USB networking
- N900 runs on modified titan's power-38 kernel.

(edit) The top option works fine, it just opens up top process much like windows' task manager for those windows users out there. (/edit)