JSON returned from listdata.svc for a full list, but "XML" for a single item

I've been trying to use jQuery to get some data from a SharePoint list named Articles, using REST.  Hit a wall, couldn't figure it out.  Quick blog post about how I got around it.

Basically, when I tried to use $.getJSON with this URL:

http://sharepoint/_vti_bin/listdata.svc/Articles()

I was able to parse the data in jQuery as you'd expect.  Worked like a dream.  However, when I tried to just return one single list item, using:

http://sharepoint/_vti_bin/listdata.svc/Articles(1)

jQuery silently failed.  Couldn't get any data out of it whatsoever.  When I looked at Google Chrome's Developer Tools (specifically, the Network function), I could see that Articles() was being returned as application/json as you'd expect, but Articles(1) was being returned as text/plain.  jQuery didn't like that.

So, I added a parameter to my URL:

http://sharepoint/_vti_bin/listdata.svc/Articles(1)?format=JSON

And everything is right in the world again.