Gem update is not working from 10 days

Hi All,

I used to update gems installed in my Ubuntu 12.04 OS computer with gem update command.

But this is not working from 10 days.

Any configuration changes changed/need to be done.

How to check, can any one let me know.

Log

*@:~$ gem update -V
Updating installed gems
HEAD https://rubygems.org/specs.4.8.gz
302 Moved Temporarily
HEAD https://s3.amazonaws.com/production.s3.rubygems.org/specs.4.8.gz
304 Not Modified
GET https://rubygems.org/prerelease_specs.4.8.gz
302 Moved Temporarily
GET
https://s3.amazonaws.com/production.s3.rubygems.org/prerelease_specs.4.8.gz
200 OK