G4 and SLEEP - again

After I have rebooted my G4 it will go to sleep automatically but JUST THE FIRST TIME.
PeterG wrote on :

After I have rebooted my G4 it will go to sleep automatically but JUST THE FIRST TIME. Thereafter it will only sleep when I press the monitor button.

SYSTEM: macintosh G4; 466Mhz; OS 10.3.5; 896 Mb RAM

I have looked at the Apple info site but nothing seems to work for me.

Any ideas/ suggestions?

Cheers and thanks.