In current master (not the 0.9.2 available on backbonejs.org) there seems to be something preventing .create() from adding the model to the collection when wait:true. I couldn't spot the difference between 0.9.2 and master, but moving (or eliminating) the deletion of options.wait in the .save() method seems to fix the problem, but I'm not sure what other repercussions that has.