Hi folks, I want to help with the multilingual support of silverstripe, since this is very important to me. I can do a lot of work with _t() functions and also finish the spanish translation. Now to the problems.

In NewsletterAdmin_SiteTree.ss

<% _t('DRAFTS','Drafts') %>
<% _t('SENT','Sent Items') %>
<% _t('MAILLIST','Mailing List') %>

do not care about language files. I'm using es_ES locale, and this strings are not translated at all, and they are present in the language file. Even changing them in the en_US.php results in no change. The only way I can change them is changing them inside the .ss template. Why? I have the same problem with some strings in the svn version of the blog module.

I'm trying to complete the multilingual support adding _t() functions, and adding the new translation array to en_US and es_ES.php, but this doesn't let me go further. This things unmotivate me. PLEASE HELP.

SSViewer (the template parser) and the textcollector have different ideas on which namespace the entities should be found - an inconsistency in i18n core. i've created a ticket:
http://open.silverstripe.com/ticket/2584

this took me nearly two hours to debug, phew... sorry i can't help more right now, its a pretty tricky thing to fix.