tested your latest version in 2.1 elgg and pagesetup event is gone

[propertunist]

the sidebar modules do not load in the version for 2.0 that you have on your website - when testing in elgg 2.1. the pagesetup event has been removed from core, so the handler for that event needs to move to another event.

[propertunist]

i resolved this by replacing the call to the event in the init function with:

    if (elgg_in_context('activity'))
        river_addon_pagesetup();

[propertunist]

oh, though that may be an issue for the group activity page.. hm

[propertunist]

the elgg community informs me that the pagesetup event is not gone from 2.1, however, river_addon (like the plugin login_as and some others) does not play nicely with the pagesetup event for some reason for me in 2.1.