The "put computer to sleep" feature in the Energy Saver panel has quit working in my G5 Mac running OSX ("put display to sleep" still works and I can still put the computer to sleep manually).
The problem occurs even if no applications have been opened, so it does not appear that any particular application is causing the problem.
I did upgrade from OS 10.3.2 to 10.3.9 a while back because that was necessary to get Brother Printer MFC 9420CN to work. The problem dates from about that time so may be related to the upgrade or the printer. I disabled all options in the Brother ControlCenter but that didn't help.
Any comments much appreciated.