Load data from CSV drops the modal, but load doesn't do anything

I see this in the Firefox developer console after I click load.

```
[22:04:03.853] TypeError: field is null @ http://explorer.datahub.io/vendor/recline/dist/recline.js:1003
```

The same CSV works fine when I use **Load from CSV online**. The CSV I've been using is this one: http://data.london.gov.uk/datafiles/transport/tfl_passengers.csv
