I'm new to JSON, so this may be an easy fix, but for the life of me, I can't figure it out.

I've got a JSON string being returned by an external server application, that's basically formatted like this:

Code:
{"total":1,
"results": [{
	"id":"71",
	"recordtype":"customrecord_recordtype",
	"columns": {
		"name":"Record Name",
		"internalid":{
			"name":"71","internalid":"71"
		},
		"custrecord_itemsused":{
			"name":"Item",
			"internalid":"4"
		},
		"custrecord_date":"2014",
		"custrecord_image":{
			"name":"/core/media/media.nl?id=1234&c=1234&h=abcdefg",
			"internalid":"269327"
		},
		"custrecord_icon":{
			"name":"/core/media/media.nl?id=5678&c=5678&h=hijklmn",
			"internalid":"269322"
		},
		"custrecord_latitude":"30",
		"custrecord_longitude":"-120"
	}
	}]
}
I'm running through a building elements on a Google map. For the most part it works fine, but I can't seem to access the name of custrecord_image or custrecord_icon URLs without getting an error. Based on what I've read, the syntax would be as follows:

Code:
jsonResponse = JSON.parse(jsonResponse);
var image = jsonResponse.results[i].columns.custrecord_image.name;
var icon = jsonResponse.results[i].columns.custrecord_icon.name;
But that throws the following error:

Code:
Uncaught TypeError: Cannot read property 'name' of undefined
And to add an extra level of weirdness, when I just build the JSON as a string locally and test it, everything works fine. But, when it's returned from the server, it produces the error. Also, accessing custrecord_itemsused with the following syntax works fine:

Code:
var itemsused = jsonResponse.results[i].columns.custrecord_itemsused.name;
Any idea what's going on here? Any help provided would me much appreciated. Thanks!