You can clone with
Here's a fiddle showcasing the issue:http://jsfiddle.net/cvndE/
My mistake, it's not the fact that they're numbers that make it die.
Could someone point out what I'm doing wrong there?
this is fixed in 3.0 version in the master branch
this may also be related to #150 in which case it should be fixed in the 2.x branch. you can grab select2.js from there and give it a go.