[object Object] and Firefox 35.0

[ad-lebedev]

Hi,
I'm using this plugin in my backbone.js application to send JSON data and files in the same request. Thats how i do it:

this.model.save(that.model.attributes, {
     iframe: true,
     dataType: 'json',
     contentType: false,
     files: this.$('form :file'),
     data: that.model.attributes
}).done(function(){...});

And it works fine everywhere, except Firefox 35.0 -- it sends me an [object Object] in request and nothing else.
Do you have an ideas, what i'm doing wrong?

[abologna-r7]

same here 👍