HI, i am working in Rails .. my gem list is
*** LOCAL GEMS ***
abstract (1.0.0)
actionmailer (3.0.4, 3.0.3, 2.3.11, 2.3.10, 2.3.8, 2.3.4, 2.3.2)
action
OK I just upgraded a Rails app from 2.3.4 to 2.3.14 and got the same error.
However I had already downgraded rubygems to 1.3.5 (as recommended in another answer) to get around a similar error after upgrading the core Ruby package
So i took a punt and upgraded to the latest version:
sudo gem update --system
This gave me version 1.8.24
and everything started working again. shrug
Perhaps that throws the issue into a somewhat different light.