Duplicated comments on groups wall - cool_theme

Hi all, I searched through the groups and discussions and couldnt find an answer to the issue I'm having (I saw other people has this issue too).

This is the issue: On a group's wall, when you post a comment on the wall, the comment is repeated in every item listed in the river. Here is the issue happening: http://grab.by/gmUw (sorry my site is in spanish), those are "Join" action types, people joining to the group, and notice how the 3 comments are shown in all the "join" action types (in the screenshot I just show 2 places where its repeated but its repeated in all the join items).
These 3 comments were created by users here http://grab.by/gmUI, as a Wall comment, not as a comment in the "join" item, know what I mean?

So, I guess the trick is to manipulate the joins and wheres options in elgg_list_river. This is how I have it right now http://grab.by/gmV6.

Any advice on how to get rid of the duplicates? These 3 comments should be shown only as an individual post on the wall.

Thanks in advance!