Safari 6.0.5 Mac won't "SAVE IMAGE AS" jpegs from web pages

Hi. Trying to figure out what has changed here.

In the past, when I've located a specific graphic on a web page — say, a .png or .jpg file through a Google image search in Safari — I could right click and choose "SAVE IMAGE AS" and download the image to my desktop.

No more.

Now Safari insists on appending ".webarchive" to the end of the file (for example, "image.jpg.webarchive" or "image.png.webarchive"), but won't let me download it. I tried to "SAVE IMAGE AS" a file called 27.png from a web page, for example, and got this error message:

If I try to remove the ".webarchive" extension, I get this error message:

I used to be able to simply right click an image, select "SAVE IMAGE AS" and save .jpg and .png files to my desktop. It still works that way in Firefox.

I am not looking for workarounds or other ways to do this, as I have spent many years doing it this way and it has become habit; I am trying to find out how I can get the old Safari behavior back. Any ideas on why this behavior changed in Safari and how I can revert?