[horde] Does username hooks apply to calendars, tasks etc?

[Luis Felipe Marzagao/Andamentos]

I have successfully set up username hooks in order to add or strip the 
domain name from/to the userid, so my users see "john" instead of 
"john at example.com". But it only works on the horde portal view. When the 
user clicks on calendars, task or mnemo, the sidebar shows 
"john at example.com" instead of just "john". So I wonder if the username 
hooks are globally applied to all horde modules (in which case I´m doing 
something wrong) and in case it´s not meant to be global, how could 
manage to do it?

Thanks a lot.
Luis Felipe (duli)