the '-->' is (or should be) the end of a HTML comment and should be invisible for normal visitors of your blog.
But it appears because the there is a comment in a comment in the source code of your posts.
The podPress code starts usually with a comment:
<!-- Begin: podPress --> and ends with
<!-- End: podPress -->. The purpose of these comments is to make the podPress section easier to spot among all that other code if some one searches for it in the source code.
In the case of your blog the second podPress section is inserted into a section which is surrounded by such a HTML comment and the comment signs inside a comment confuse the web browsers a little and the closing tag of the surrounding tag gets visible because an other comment closing tag ends the comment.
<!-- <p>Christian Vagedes von[...] <!-- Begin: podPress --> [...] <!-- End: podPress --> </p> -->
The "-->" after "Begin: podPress" closes the comment and the rest is visible.
That is why the second player (per post) is visible.
The second player exists most likely because the template file contains the PHP function call of
the_content(); two times per post. podPress uses the WP Action Hook the_content to add the player and the other elements each time that function is called.
It is also possible that this section contains a call of
the_excerpt();. podPress adds its elements also to excerpts.
However, you should look into the template file of your theme which produces this page (maybe index.php) and use a PHP comment instead of a HTML comment to hide this part.
<!-- <?php the_excerpt(); ?> -->
<?php // the_excerpt(); ?>