I know this won't help anyone debug but I just tried running gem
update on my Fedora Core 3 install and it seqfaulted.

I think the reason is that most of my upstream bandwidth was busy as
was my downstream was being used and possible the download stopped.

I had a similar problem earlier today in Windows when I was trying out
a Java Webstart application. My first attempt dropped out with an
exception (zip stream error) and the second time was fine.

Rob
-- 
Personal responsibility is battling extinction.