Do not know how to solve following question..
I have -current system with some things like XFree86, libpng built from
sources and installed in /usr/local. 
I wanted to install mozilla, but it is too much pain to build it from sources.
So I downloaded packages from /pub/NetBSD/packages:
mozilla-stable-1.7.3.tgz
ORBit-0.5.15nb7.tgz
freetype2-2.1.9nb1.tgz
gdk-pixbuf-0.22.0nb3.tgz
glib-1.2.10nb8.tgz
gtk+-1.2.10nb8.tgz
jpeg-6bnb3.tgz
mozilla-fonts-1.0.tgz
png-1.2.8.tgz
tiff-3.6.1nb6.tgz

I pkg_added them.  Mozilla works but it fails to show any images.
All images, including images on buttons.
Don't anybody know how this can be cured?