Russian name causes AP to not display

I'm using AP 6.x-2.0-alpha2 and AF of the same version.
Author Pane is displayed correctly in forum comments, but there is no it in main post.

In the corresponding template advanced_forum.naked.post.tpl.php
there is section

<div class="forum-post-wrapper">
<div class="forum-post-panel-sub">
<?php print $author_pane; ?>
</div>
</div>

it should work both for post and for comments
but in the forum post section I see in html page only

<div class="forum-post-wrapper">
<div class="forum-post-panel-sub">
</div>
</div>

if I write smth like

<div class="forum-post-wrapper">
<div class="forum-post-panel-sub">

<?php if ($top_post): ?>
<?php print $name; ?>
<?php endif; ?> 

<?php print $author_pane; ?>
</div>
</div>

I see author name in post section.
So it seems that $author_pane variable is undefined in forum main post.
What can I do with it?

No, it is standard forum topic node. No special modules.
Special things, that I can see now - author pane is not shown when user real name is in non-english (russian) language.
When the author of first post has english-written name - it is all OK with author pane.
If in russian - there is no author pane in the main post - only in comments.