trouble with Imagemagick and Rails 2.3.5

After upgrading to Rails 2.3.5 I got a runtime error message from a previously running well application (w Passenger) dont' see where to start looking for a solution... help appreciated ;-))

error message from Passenger This installation of RMagick was configured with ImageMagick 6.5.8 but ImageMagick 6.4.8-7 is in use. ..

backtrace 0 /usr/local/lib/ruby/gems/1.8/gems/rmagick-2.12.2/lib/ RMagick2.bundle 1 /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb 31 in `require' 2 /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/ active_support/dependencies.rb 158 in `require' 3 /usr/local/lib/ruby/gems/1.8/gems/rmagick-2.12.2/lib/RMagick.rb 11 4 /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb 36 in `gem_original_require' 5 /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb 36 in `require' 6 /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/ active_support/dependencies.rb 158 in `require' 7 /Users/yves/Developpement/Projects/isabelle/atelier/app/controllers/ aquarelles_controller.rb 1 8 /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb 31 in `gem_original_require' 9 /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb 31 in `require' 10 /usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/ active_support/dependencies.rb 158 in `require'

from install log .. ---> Installing ImageMagick @6.5.8-0_1+q16 ---> Activating ImageMagick @6.5.8-0_1+q16 ... Successfully installed rmagick-2.12.2..

where could be located ImageMagick 6.4.8-7 if it's in use ?

thanks fyh

erwin