To sleep, perchance to dream? OS 10.2.8 - ay, There's the Rub

Hi all,
I recently updated to 10.2.8 (2 years late, but I tend to be cautious
:-/ ) on my dual 1GHz G4 tower with a 23" Apple display.
Now I cant get the machine to waken from sleep mode. The CPU fires up
but the screen remains blank and I have to restart the Mac. 
Any fixes/patches out there?

Trusting my caution, I failed to make a backup of the OS before I
upgraded from 10.2.3. If no fixes are available, how can I downgrade
again? I have the original 10.2.1 CDs.  Start again and upgrade to
10.2.3? Is it still available?

Thanks

Ray