Thanks Ouija, I knew some brave heart like you would do such favour the rest of the community.
Since I also tried and couldn't yet solve the sleep issue, i am now just using 10.5.7. As on 10.5.8 I also had the same sleep problem.
You mentioned that you were on 10.5.8, was it also using the chameleon installation method? How was the sleep, restart, and shutdown function there? If you have those working completely, could you post your solution? (I have tested that, the fix kext for the 10.5.6 didn't work for 10.5.7; and my fix didn't work for 10.5.8). Thanks!