bug: unable to turn on "Show date and time in menu bar" All of a sudden, I had the date and time on the menu bar of my 10.6 machine vanish. I tried turning it on in the "Preferences >> Date and Time" section but I'm not able to.

Anyone got similar problems/found a solution to this?

If there's any additional information I can provide you, please let me know. Thanks in advance!
It's possible com.apple.menuextra.clock.plist located in your user /Users/yourShortNameHere/Library/Preferences is corrupted. 

Close the System Preferences window. Move that plist out of its directory, and re-launch the System Preferences.

Feedback if it doesn't work.