Right. And also keep in mind that Firefox will change the selection color based on the inherent background color of the element being selected.

So, if you've got a black background of a super-parent element, and an light-colored image background for the parent or the element, your text will highlight white, ensuring that selected text is unreadable in certain situations.

Either the posted hack or setting a background color fixes it.

Seems like a much better solution would be to set a light-colored background color to the element which has the background image.