plugin from CRM 4.0 to CRM 2011 does not execute

Hi,

I have a plugin that used to work on CRM 4.0 (personal default view manager: http://a33ik.blogspot.ca/2009/06/personal-default-views-manager-for.html). I managed to register the plugin in CRM2011 with no errors, but it does not execute. Any idea why? 

Thank you,

Alina