Created attachment 270540 [details] snap of page showing bad stuff... If you load this page, you will see: "There should be a green box below." With 188.8.131.52, I do see a green box. With the trunk build, I see a red box with some small green boxes placed inside. Will attach a snap.
That displays fine here (both Camino and Minefield latest trunk builds, 10.4.10 ppc). There is a brief flash of red while the background image loads.
Worksforme. Taking snapshots onload might not work because of the background image, of course...
I will confirm, when I get a copy of FF that has the fix to bug 253851, that it works.
When the page completely finishes loading, the box is green. This is observed with a trunk build from July 11.