I get this message in httpd/error_log. To fix, I check to see if isset($GLOBALS["current_collection"]["id"]) first in plogger_collection_album_count. The func now looks like:
function plogger_collection_album_count() { if (isset($GLOBALS["current_collection"]["id"]) && isset($GLOBALS["album_count"][$GLOBALS["current_collection"]["id"]])) { return $GLOBALS["album_count"][$GLOBALS["current_collection"]["id"]]; } else { return 0; }; }