Excuse me, but in manual of nagios I find that from release 2.XX this part is changed..
You don't create any new hostextinfo.cfg file, but you edit the host.cfg file with same instruction that you write above.
To confirm what I say you can find this :
* New location - Extended host info and service info definitions are now stored in object config files along with host definitions, etc. As a result, extended info definitions are now parsed and validated by the Nagios daemon before startup.
* New directives - Extended host info and service info definitions now have two new directives: notes and action_url. "
Infact I edit as I read in documention, and every icons are loaded ecxept on status Map.
So I ask a confirm what understand...
Probably I have a mistake caused from my bad english..