Redmine

I'm trying to set up link between issue and my model class in the plugin.
It works very well from ruby console (Issue.destroy(some_id) destroys also and my object (record in my table)) and on server production mode.
But unfortunately it doesn't work in development.
Can somebody help me to understand this problem and to find some solution?

my class:

class MyEntity < ActiveRecord::Base
unloadable
belongs_to :issue
end


patch for issue:

module IssuePatch
def self.included(base)
base.class_eval do
unloadable
has_one :my_entity,
:dependent => :destroy
end
end
end