Why can't I shut down my MacBook unless I hold down the power key?

Question

Hi all,
I have had this problem my MacBook Pro using both Leopard and Jaguar. It is a problem when I shut down using either the drop down menu or by the power key menu. It appears to shut down but when I close the lid the "sleep" light comes on and is steady. It isn't actually shutting down because if I don't have the power charger plugged in it will run out of charge.
So, to shut down, I hold the power key down for about 10 seconds.
If it does fall asleep I am unable to awaken it (the sleep light is steady) and have to go through the holding down the power key procedure to shut it down and then use the power key to start it back up.
Am I damaging it by doing this? I have tried the trouble shooting options as described in the manual. I had this problem before and one day it just wouldn't turn on and I had the hard drive replaced.
Thank-you very much for any help!
Becky Bell
Sydney AUS
Model Name: MacBook Pro 17"
Model Identifier: MacBookPro1,2
Processor Name: Intel Core Duo
Processor Speed: 2.16 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 2 MB
Memory: 1 GB
Bus Speed: 667 MHz
Boot ROM Version: MBP12.0061.B03
SMC Version: 1.5f10
Serial Number: SystemSerialNumb
Sudden Motion Sensor:
State: Enabled

Answer 1

I have found a solution on another thread that seems to have solved the problem for me. That is, I haven't experienced since, either the double password prompt at wake from sleep or the issue of not being able to shutdown.
The solution requires deleting a preference file that apparently carried over from Tiger in the upgrade to Leopard and which is causing all the problems described. Preference files or .plist files hold configuration preferences and settings generally defined by the user for a particular operating system function. Deleting one of these files will result in the system recreating it on reboot with all settings set to default values, this is a simple way of fixing an incompatible/corrupt preference file.
WARNING: Deleting preference files will reset all configurations for that files associated function. Custom user settings made in the +system preferences>Hardware>Energy Saver+ preference panel will have to be re-configured by the user.
*_Step 1:_* Delete .plist files
/Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist
/Library/Preferences/SystemConfiguration/com.apple.AutoWake.plist (may not be necessary, holds schedule details for the Energy Saver preferences)
*_Step 2:_* Reset Parameter RAM
+Resetting PRAM and NVRAM+
1. +Shut down the computer.+
2. +Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.+
3. +Turn on the computer.+
4. +Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.+
5. +Hold the keys down until the computer restarts and you hear the startup sound for the second time.+
6. +Release the keys.+