I'm not sure why you added something I didn't say in my post... Let's try again.
1. Fresh boot of computer, Win8 theme loads. Clock is missing.
2. Change from Win8 to any other theme. Clock shows up.
3. Change back to Win8 from that other theme. The clock shows up.
It's only missing from Win8 on first load. Subsequent loads of the Win8 theme show the clock.