From: Caleb Tennis <caleb@...>
Date: 2006-07-08T04:42:27+09:00
Subject: Re: Problem installing gem

> That's one of the first things that came to mind, so I specifically
> checked that both "zlib" and "zlib-dev"(or whatever it's called) are
> installed.  Makes no difference.

Have you tried uninstalling and reinstalling ruby and its related packages 
after making sure zlib and zlib-dev are installed?