I'm using my own theme and the newest blog modul (checked out from http://svn.silverstripe.com/open/modules/blog/trunk) with the language assistance. There ist the Blog Entry.ss file:
<!--------------------------------------------- -->
<% include BlogSideBar %>
<div id="BlogContent" class="typography">
<% include BreadCrumbs %>
<div class="blogEntry">
<h2>$Title</h2>
<p class="authorDate"><% _t('POSTEDBY', 'Posted by') %> $Author.XML <% _t('POSTEDON', 'on') %> $Date.Long | $Comments.Count <% _t('COMMENTS', 'Comments') %></p>
<% if Tags %>
<p class="tags">
<% _t('TAGS', 'Tags:') %>
<% control Tags %>
<a href="$Link" title="<% _t('VIEWALLPOSTTAGGED', 'View all posts tagged') %> '$Tag'" rel="tag">$Tag</a><% if Last %><% else %>,<% end_if %>
<% end_control %>
</p>
<% end_if %>
<p>$ParsedContent</p>
<br />
</div>
<% if CurrentMember %><p><a href="$EditURL" id="editpost" title="<% _t('EDITTHIS', 'Edit this post') %>"><% _t('EDITTHIS', 'Edit this post') %></a> | <a href="$Link(unpublishPost)" id="unpublishpost"><% _t('UNPUBLISHTHIS', 'Unpublish this post') %></a></p><% end_if %>
$PageComments
</div><!--------------------------------------------- -->
You see the $PageComments? This is not from the blog module!
Inside the folder cms/lang are the language files, e.g.
$lang['en_US']['PageCommentInterface_singlecomment.ss']['REMCOM'] = 'remove this comment';
But they translation does not work on my BlogEntry Page.
I also tried to change to
$lang['en_US']['BlogEntry.ss']['REMCOM'] = 'remove this comment';
but it's not working.