(SystemStackError) Unit Tests Not working

Hi,

Please Help, I am trying to run tests on my website but it fails each and every time I think its not even running test. ruby version: ruby 1.8.6 (2008-03-03 patchlevel 114) [x86_64-linux] rails version: Rails 2.3.5

when I did this from console ruby test/units/activity_test.rb

it throws this error (and no other test is running) /usr/lib64/ruby/gems/1.8/gems/mysqlplus-0.1.1/lib/mysqlplus.rb:18: warning: parenthesize argument(s) for future version /usr/lib/ruby/site_ruby/1.8/rubygems/source_index.rb:324:in `search': stack level too deep (SystemStackError)         from /usr/lib/ruby/site_ruby/1.8/rubygems/source_index.rb: 323:in `select'         from /usr/lib/ruby/site_ruby/1.8/rubygems/source_index.rb: 323:in `search'         from /usr/lib64/ruby/gems/1.8/gems/rails-2.3.2/lib/rails/ vendor_gem_source_index.rb:119:in `search'         from /usr/lib64/ruby/gems/1.8/gems/rails-2.3.2/lib/rails/ gem_dependency.rb:78:in `specification'         from /usr/lib64/ruby/gems/1.8/gems/rails-2.3.2/lib/rails/ plugin/locator.rb:81:in `plugins'         from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb: 31:in `inject'         from /usr/lib64/ruby/gems/1.8/gems/rails-2.3.2/lib/rails/ plugin/locator.rb:81:in `each'         from /usr/lib64/ruby/gems/1.8/gems/rails-2.3.2/lib/rails/ plugin/locator.rb:81:in `inject'          ... 2476 levels...         from ./test/unit/../test_helper.rb:2:in `require'         from ./test/unit/../test_helper.rb:2         from test/unit/activity_test.rb:1:in `require'         from test/unit/activity_test.rb:1

My test case is very simple

this is my activity_test.rb

require File.dirname(__FILE__) + '/../test_helper'

class ActivityTest < ActiveSupport::TestCase

  def setup   end

  def test_per_page     assert_instance_of Fixnum, Activity.per_page   end end

I do not having any idea why its not running. Please help

Thanks Sumeet