Firefox 3 displays pieces of desktop background

[Warren Liddell]

Firefox 3 has been rendering some corrupted images for me since its
> release.  Some images would render as fully or partially black, others
> would render with bits of Firefox toolbar and even others would render
> with different portions of the web page and other X11 applications.
> Xorg log would show spammed "Render bad image" messages.  Opera renders
> correctly, except it breaks malloc (e.g. mplayer will fail to allocate
> memory while Opera is running).  I've kept ports up to date, and have
> even rebuilt all ports, but nothing fixes these problems.  These
> problems continue to occur on even the latest 7-STABLE builds.
>
> Best Regards,
> Nathan Lay

I myself have had this issue for a little while myself. Pictures 
partially display and rest black or picture displays as complete back or 
as also mentioned, parts of the toolbar in firefox or the desktop 
appear. I running an upto date ports/source etc on a 7.1-PreRelease 
AMD64 machine.