Meteor Autorun() not running when accessing collection.property -

something strange going on; when run following code, works:

deps.autorun(function() {   var room = rooms.findone({'room_id':session.get('room_id')});   // var p = room.room_id;   console.log('autorun'); } 

however, if uncomment var p line, (the whole block) stops running. what's happening?

found in depths of meteor.js documentation: "if initial run of autorun throws exception, computation automatically stopped , won't rerun."

on first run of autorun, when page loaded, database hasn't been loaded throws exception when try access room.room_id, , autorun stops running again. fixed adding:

if (room) {   console.log(room.room_id);   ... }