can someone explain why I am seeing these ?

Jun 20 02:00:53 netbsd /netbsd: APM set CPU idle:unknown error code? (83)

but whatever it is due to, with NetBSD power saving kicks in on
my monitor due to BIOS settings which is good.  Also, I saw this:

Jun 19 23:59:12 netbsd /netbsd: /usr: optimization changed from TIME to SPACE
Jun 19 23:59:29 netbsd /netbsd: /usr: optimization changed from SPACE to TIME

and /usr is:

/dev/wd1f          175663    89250    77629    53%    /usr

(at the time I think I was installing XFree86 3.3 - i.e. /usr might have
 gone from sub 50% to 53%, if it changed even that much!)

Darren