Problem with themes

i have updated my themes to work with rails 1.2.3 on my development
machine… but the problem i am having is that when i try to run the same
app on my production machine, i am getting the following error… (see
below)

does anyone have any idea what this might be?

thanks!

** Starting Mongrel listening at 0.0.0.0:8003
** Starting Rails with production environment …
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:21:in
require__': no such file to load -- patches/actionmailer_ex (MissingSourceFile) from /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:21:inrequire’
from
/usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active_support/dependencies.rb:495:in
require' from /usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active_support/dependencies.rb:342:innew_constants_in’
from
/usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active_support/dependencies.rb:495:in
require' from /home/fastcast/railsapps/podcaster/config/../vendor/plugins/theme_support/init.rb:4:inload_plugin’
from
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/initializer.rb:401:in
load_plugin' from /usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.2/lib/active_support/core_ext/kernel/reporting.rb:11:insilence_warnings’
from
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.3/lib/initializer.rb:401:in
load_plugin' ... 11 levels... from /usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/bin/mongrel_rails:83:inrun’
from
/usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/lib/mongrel/command.rb:199:in
`run’
from
/usr/local/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/bin/mongrel_rails:235
from /usr/local/bin/mongrel_rails:18