[MACEP] Mac Keyboard conondrum

[Dave Baasch]

Color me clueless.

Situation:  An older iMac DV (500MHz G3) runing 10.2.8, stable for years. 
OEM  USB keyboard's space bar suddenly "quit working". Couldn't be 
dissassembled for cleaning, so a new Apple keyboard was purchased.  It 
exhibited exactly the same behavior - every key worked except the spacebar!

Eventually I determined that the spacebar key works electrically: if I hold 
down the option key simultaneously a space appears (whether this is a 
standard "hex20" space or a something else-space I didn't determine, but 
the key itself actually works)

Since I wanted to upgrade to Tiger anyway, I did, expecting the problem to 
disappear, but it didn't.

So  - where do I tweak to fix it?  Any thoughts are appreciated, including 
"You doofus - here's the answer at Apple's support site."

Dave Baasch