HTTP Response 302 fetching

Hi, I am moving to mac os x 10.5.6 and wanted to update rails from Rails 1.2.6 to something higher, so I typed in my terminal sudo gem update --system it just doesn't seem to work. Always when I try to update in terminal it gives me out this error : ERROR: While executing gem ... (Gem::RemoteSourceException)     HTTP Response 302 fetching | your community gem host Anyone can help me?