Some theme images still wrong in 1.10.4

Just over a year, #9090 was filed, indicating that some theme images were wrong.

I think this is still happening in 1.10.4. As you can see here, the background on my super-simple accordion is wrong: http://jsfiddle.net/a7nST/

If I just swap out the background file with the one served up by themeroller, suddenly it looks right: http://jsfiddle.net/xc5u3/1/