Mac G4 Tiger Wakeup Problem


I just did clean install of tiger on old 400Mhz powermac G4 (with 320MB and replaced HD) - including latest updates to 10.4.2 and installed no other (non-apple) software. Everything looked fine until I put it to sleep and then waking up it just hangs for 1 minute and then has "You need to restart your computer..." message. There is nothing plugged in but keyboard, mouse and monitor and no application running when I put it to sleep. It works fine from cold boot or restart. I tried setting all the energy saver function to not wakeup (per but did make a difference. Any suggestions appreciated.