Perhaps this message is only to Jim Perrin...
Not that I've specifically have had any issues that I can point to...
almost at the top of http://www.rubyonrails.org/down
We recommend Ruby 1.8.4 for use with Rails. Ruby 1.8.2 is fine too, but version 1.8.3 is not.
Myself, I have sort of backed off on the rails development for the moment and am becoming intimately lost in ruby itself and am presently working on my Fedora Core - 4 system which has ruby-1.8.4 but I am going to get back rails development on the CentOS system when I have begun to fill in the cavernous gaps of knowledge that are holding me back.
Craig