Firefox find broken for XML?

Someone verify that I’m not crazy, but is firefox not able to find text within a rendered XML document?

For example, go here:
http://www.yahoo.com/crossdomain.xml

Type CTRL+F
Then type yahoo

The phrase is not found. If you view the source and do the same, it is found.

I tested this with Windows XP, Firefox 3.5, but I thought I saw someone do this and have it work on Mac?