Hi there,
I just noticed that the top two entries in Setting -> Usage just show as blank "------" - and I can see that there is a notification about "usage will show when fully charged" - however this does not seem to happen.... I have reset the phone, restarted and the likes - but to no avail.... anyone else seeing this?

If you restart the springboard those details reset. I've only seen it work once and that was a while after a 100% charge didn't last long though cause I installed a new application

How do I restart springboard?

there should be a few apps in installer for that like kill board and respring