Can't update ActiveSupport gem

I'm getting the message

ERROR: While executing gem ... (ArgumentError) string contains null byte

My RAILS implementation is now completely out of sync. All other gems are updated to latest except ActiveSupport. rake rails:update:configs is aborting because ActiveSupport is wrong version.

Any help would be appreciated!

Now I'm totally hosed. I tried to reinstate an older version of RAILS, and I can't start my server. The error I'm getting is:

Exiting /usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.3/lib/ active_support/dependencies.rb:477:in `const_missing': uninitialized constant Gem::Version::NUM_RE (NameError)         from /usr/local/lib/ruby/gems/1.8/gems/loaded_plugins-0.1.2/ lib/loaded_plugins/plugin.rb:19:in `name_for'         from /usr/local/lib/ruby/gems/1.8/gems/loaded_plugins-0.1.2/ lib/loaded_plugins/plugin.rb:27:in `initialize'         from /usr/local/lib/ruby/gems/1.8/gems/loaded_plugins-0.1.2/ lib/loaded_plugins/extensions/initializer.rb:23:in `new'         from /usr/local/lib/ruby/gems/1.8/gems/loaded_plugins-0.1.2/ lib/loaded_plugins/extensions/initializer.rb:23:in `load_plugin'         from /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.4/lib/ initializer.rb:189:in `load_plugins'         from /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.4/lib/ initializer.rb:189:in `each'         from /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.4/lib/ initializer.rb:189:in `load_plugins'         from /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.4/lib/ initializer.rb:109:in `process'          ... 29 levels...         from /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.4/lib/ commands/server.rb:39         from /usr/local/lib/ruby/site_ruby/1.8/rubygems/ custom_require.rb:27:in `gem_original_require'         from /usr/local/lib/ruby/site_ruby/1.8/rubygems/ custom_require.rb:27:in `require'         from script/server:3

Help please!

Fixed.

Don't know what happened but reinstalling ruby gems did the trick. Running now on rails 1.2.4. Still have question about download failure of Rails 1.2.6 gem.