IMAC G3 KEYBOARD PROBLEM

I would try another USB keyboard as a test. It does not have to be a +Mac specific+ keyboard. If that other keyboard does not have this issue, the most likely problem is that the your current keyboard is becoming faulty.

Also, if you have not already, try using a different USB port. Also try it with all other USB devices disconnected, to see if this problem recurs. If you use a USB hub, connect the keyboard directly the Mac and disconnect the hub too.

Did you spill something in the keyboard? Is it dirty? I would blow it out with compressed air (a air can).

Missmom,

Sometimes all the keys (including spacebar) on the bottom 2 rows of the keyboard will not work. I can hold down a key for a few seconds & eventually it might spit out several at a time. When it's in this mood, I have tried restarting and sometimes that helps, but lately it has been happening more frequently

Well if it's not a software problem...
Most keyboards are built like this one:
http://www.lifehack.org/articles/technology/how-to-repair-a-computer-keyboard.ht ml
so if one of the lines you see get's damaged then the keys on that whole line can get wacky.
I repair a lot of these for donation and what I see is a bit of liquid gets into the keyboard and damages one of those lines you see. It doesn't take much and it can take years for the damage to show up.
Try a different keyboard like Kenichi says and see if your problem goes away.
Richard

Message was edited by: spudnuty

If you are using a hub, I would use the kind that is self-powered (has its own power supply rather than drawing power from the USB bus).