Komento Activity stream cause 500 error page on JomSocial FrontPage

Hi,
we have a problem with Komento when user comment a post it break JomSocial Frontpage page.

Infact, after comment to EasyBlog post
if i try to go on http://localhost/web/mysite/index.php?option=com_community&view=frontpage&Itemid=124

it returns error 500 page.

If we in Backend delete Last Activity Stream for Komento the page return to work.

Note: we have also tried to update to actually latest versions (Version 1.5.3200) but error still appears.

Please Let us Know,
Regards