iMac+Ubuntu

[illgiveumorality]

I inherited a good old G3 iMac. So, having a copy of ubuntu linux (or 40), I figured I'd try it out. The installation took forever, but there were no errors. After the computer booted up, it prompted me with a login screen, but if I tried to log on, the computer would lock. I figure I could try re-installing, but with my past attempts to install it on my mac mini, I have a feeling it won't work. Any hints?
Thanks.

[LesterOfPuppets]

I think Yellow Dog Linux would be a better choice for a G3, I've only tried it on a G4, however.