I’ve written before about my problems getting Safe Sleep / Deep Sleep to work on my MacBook Pro. More frustrating was I couldn’t seem to disable it fully: I could disable it temporarily, but as soon as my laptop used a different Energy Saver preference [which happened automatically when it was unplugged from the power supply], it would immediately re-enable Safe Sleep.
Turns out that this 10.4 tip on Mac OS X Hints works just fine on 10.5 as well. The secret, for me, seemed to be the second line, which doesn’t show up in all the explanations of how to disable it:
$ sudo pmset -a hibernatemode 0
$ sudo nvram “use-nvramrc?”=false
It’s been a couple of weeks since I configured things this way, and it hasn’t reset itself, so it’s working out nicely.