It does not have a problem going to sleep. It is like a narcoleptic computer. It falls asleep randomly in the middle of movies, games, typing, etc. and sometimes goes days or weeks without acting up or it could be every 10 seconds, sometimes it will sleep for long periods or short periods. It is completely random.
I found a few other posts throughout the internet with a similar issue and the initial response was usually the same :
"Try resetting the PMU. Its a different process depending on which model powerbook you have. Usually involves disconnecting AC power and removing the battery then holding the power button for 5 seconds. Then putting the battery back in and turning it on again. But yours may be different."
I had tried that myself, among other things, before taking it to a Mac store to have it evaluated. They charged me $100 to look at it and told me it needed a new logic board, which would have cost $1k to fix it at the time. However, they did not confirm that it was the logic board that is the issue. The technician said it had to be due to the symptoms. I just hoped someone could confirm this before I dish out the money.