Elgg icons not showing

Sorry if this is daft or has been mentioned before (I couldn't see it anywhere).

When I post a new topic the user icon from elgg isn't transferred. It seems like vanilla is trying to call http://www.mywebsite.com/elgg/mod/profile/icondirect.php?lastcache=1277713125&username=admin&size=medium.

Navigating to this page gives; Fatal error: Call to a member function getGUID() on a non-object in   n/home/my server/public_html/elgg/mod/profile/icon.php on line 29

I have the profile plugin activated and haven't changed the vanilla css much, barely at all to be honest.

Any ideas?