Eric Meyer's article about Pure CSS pop ups opened a whole new world to me: nested containers within A tags.
The next page of this article is almost identical to Eric's tutorial but the documents which follow show a very different approach as to how to "pop up" images [or even text and images at once]. The big advantage to the technique explained here - IMO - is that the markup [to pop up images] includes empty containers so there is no need to worry about older browsers.
The solution described here is MSIE 5 Mac compatible; it also allows the use of images of different sizes.
Peter van Impelen reported that the PithHelmet plugin (for Safari), disables the styles supposed to hide the nested elements.
Note: see the source code for styles not directly related to the pop ups.