Slow to sleep

Question

I've recently upgraded from a late G3 iBook to a new White Santa Rosa MacBook, with which I'm having some sleep issues.
Firstly, the MacBook will not sleep if inactive. I've set it to go to sleep after 10 minutes of inactivity, but this does not happen. The screen goes to sleep, but the hard disk does not.
Secondly, if I close the lid or select 'sleep' from the menu, the hard disk does go to sleep but it takes about 30 seconds. The screen sleeps immediately, but the hard disk remains awake for a further half-minute or so. This is a bit annoying, as I'm used to the iBook sleeping instantaneously, and I'm loath to leave the MacBook with the lid closed and the hard disk active, for fear that it won't sleep and will fry itself.
I've tried resetting the PRAM and the PMU, but to no avail.
Any suggestions? Thanks.

Answer 1

Thanks for your response.
I didn't know about 'safe sleeping' - thanks for that. I just tried restarting. Then, with no applications running, I closed the lid; sleep came more quickly - in 15 seconds, rather than 30 seconds when a few apps are open. Still, 15-30 seconds seems like a long time to me. Is that abnormal? A friend who is also running a MacBook (admittedly, an older version) says that his machine sleeps (hard disk asleep, pulsing LED) virtually instantaneously...
As for my energy saver settings: yes the computer is set to sleep after 10 minutes, not just the screen. And the 'Put the hard disk(s) to sleep when possible' box is checked, so that shouldn't be the issue.
Any other ideas? Thanks.