ThinkPad not going properly to sleep

[Riccardo Mottola <riccardo.mottola%libero.it@localhost>]

Hi,

I have a thinkpad T30, I have NetBSD 7.0_RC2 installed.

If I hit the sleep button (moon) the computer while running X11 does 
some kind of half-assed sleep:
It closes X, on the console I quickly see "flushing disks" the blanks 
the screen, but the screen is actually "on" and the backlight 
illumination is active.
Then the "moon" led lights on.

If I hit a key, it actually comes properly back up.

Any ideas? I don't know if it used to work with older versions of 
NetBSD, my previous laptop was stolen and this is a slightly different 
model I bought as replacement.

Riccardo