bbPress.org

OK. the problem was with this custom code, which stopped working it would seem..

//* Correct Gravatars 
function bp_remove_gravatar ($image, $params, $item_id, $avatar_dir, $css_id, $html_width, $html_height, $avatar_folder_url, $avatar_folder_dir) {
	$default = get_stylesheet_directory_uri() .'/images/mystery-man.jpg';
	if( $image && strpos( $image, "gravatar.com" ) ){ 
		return '<img src="' . $default . '" alt="avatar" class="avatar" ' . $html_width . $html_height . ' />';
	} else {
		return $image;
	}
}
add_filter('bp_core_fetch_avatar', 'bp_remove_gravatar', 1, 9 );

function remove_gravatar ($avatar, $id_or_email, $size, $default, $alt) {
	$default = get_stylesheet_directory_uri() .'/images/mystery-man.jpg';
	return "<img alt='{$alt}' src='{$default}' class='avatar avatar-{$size} photo avatar-default' height='{$size}' width='{$size}' />";
}

add_filter('get_avatar', 'remove_gravatar', 1, 5);

function bp_remove_signup_gravatar ($image) {
	$default = get_stylesheet_directory_uri() .'/images/mystery-man.jpg';
	if( $image && strpos( $image, "gravatar.com" ) ){ 
		return '<img src="' . $default . '" alt="avatar" class="avatar" width="60" height="60" />';
	} else {
		return $image;
	}

}
add_filter('bp_get_signup_avatar', 'bp_remove_signup_gravatar', 1, 1 );