I have an iMac G3 here (I wonder how many people clicked back already), It had Ubuntu 5.10 installed (I gave this to a friend about 5 years ago and she never bothered updating it). Well now I got this horrible machine back to put in a DVD burner, and I figured I'd update the OS while I had it.. anyways, I tried updating to 6.06 following this page:

https://help.ubuntu.com/community/DapperUpgrades

And it did go very well, until I had to reboot. Now I have weird graphics, followed by this rather ominous message:

ALERT! //dev/hda3 does not exist

Well it existed before so just wtf did update-manager do with my root partition? tbh I might just go ahead and try the 8.x.x LTS release as it is atleast still supported.
Still I would really appreciate if someone can shed some light on what caused this to happen. Does anyone know if any of the 8.x versions work on this old iMac? if not which release am I stuck with? I don't have to give it back for a week or so, but If I can sort it before that It'll be awesome to have this ugly blue doorstop out of my living room

Hardware is as follows:

333Mhz CPU (It's in a 233 Bondi case)
256Mb RAM
Random brand 200Gb IDE hd

apparently has suffered daily use for 5 years and never produced a problem

Thanks for reading