Sleep was working fine with 10.5.7 but after updating to 10.5.8 I can sleep but can't wake from it.

in any case, my question is not how to fix it but how to disable sleep altogether since I never use it anyway. How can I prevent it from going to sleep completely? I'm not talking about moving the slider to "never" under Energy Saver but completely blocking the sleep function. I ask because sometimes when I am trying to select "Restart" I hit "Sleep" in error and it goes to sleep, forcing me to hard reset the PC.

Thanks!