When I bought my iMac at the weekend, it was running OS 9.2

After a set period the iMac went into standby and the power buttons on the front on the iMac unit would change from green to orange and pulse up and down in brightness to show it was in standby.

Now I've updated the iMac's firmware and installed OS X this does not seem to happen anymore.

I have the power saving set up as default to turn screen on, spin down disks when poss and go into power saving mode, but the LED power button just stays bright green all the time.

Also the hard drive spins up (for a few moments) every 10 minutes or so.

Just wondering if this is normal, or I need to adjust something.