BP Community and eshop-Plugin makes session error

Im using BP Community and just installed the eshop-Plugin.
All works fine, but...

When, for example, you're on Members Page. And click on Filter-Button 'All Groups' or 'My Groups', then at end of page you have the following output (see screenshot) :
Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /var/www/.../httpdocs/wp-content/themes/bp-community/groups/groups-loop.php:3) in /var/www/...../httpdocs/wp-content/plugins/eshop/eshop.php on line 1003

Found a posting in some Forum, that discussed that topic: http://www.quirm.net/punbb/viewtopic.php?id=1139

May you can help me?

Thanks in advance,
Rainer.