Avoid Ruby 1.8.7 p248 and p249 with ActiveSupport

Yesterday I updated the stage environment of Zero X to ruby 1.8.7, but after that I suddenly couldn't login anymore. The problem was a Segmentation fault in Marshal.load used by ActiveSupport:

/usr/local/lib/ruby/gems/1.8/gems/activesupport-2.3.3/lib/active_support/multibyte/unicode_database.rb:37: [BUG] Segmentation fault

ruby 1.8.7 (2010-01-10 patchlevel 249) [powerpc-darwin8.11.0]

As described in the ticket the error occurs only in patchlevel 248 and 249. So I had to go back to p174 and now everything runs smoothly again.