Fix sleep and network issues on Mac Leopard 10.5.7
Not sure what caused the actual problem but it seems that shortly after upgrading Leopard on my Macbook Pro to 10.5.7 my Macbook wouldn’t fall asleep properly and wouldn’t show all my shared computers in Finder.
I tried a variety of things but finally the simplest solution worked, I deleted the SystemConfiguration folder inside the /Macintosh HD/Library/Preferences folder and rebooted the computer.
This fixed both the sleep issue and the shared computers not showing up in Finder issue.
Good Luck.