GTK emacs can't load PNG files for themes

[Miles Bader]

When I configure CVS emacs to use GTK, it doesn't display scrollbars or
menus correctly:  menu text and background get displayed, but the
scrollbar thumb and menu highlight box are not displayed.

The reason seems to be that I use a pixmap GTK theme, and it can't load
the theme's various PNG image files for some reason.  Here's the first
few stderr messages when I start `LANG=C emacs-gtk -q >& /tmp/,emacs-errs':


   ** (emacs-gtk:17705): WARNING **: Pixbuf theme: Cannot load pixmap file 
/home/soft1/miles/.themes/MooMarble/gtk-2.0/brown_bg1.png: Failed to load image 
'/home/soft1/miles/.themes/MooMarble/gtk-2.0/brown_bg1.png': Fatal error in PNG 
image file: Incompatible libpng version in application and library

   (emacs-gtk:17705): GdkPixbuf-CRITICAL **: file gdk-pixbuf.c: line 373 
(gdk_pixbuf_get_width): assertion `pixbuf != NULL' failed

   (emacs-gtk:17705): GdkPixbuf-CRITICAL **: file gdk-pixbuf.c: line 389 
(gdk_pixbuf_get_height): assertion `pixbuf != NULL' failed

   ** (emacs-gtk:17705): WARNING **: Invalid borders specified for theme pixmap:
           /home/soft1/miles/.themes/MooMarble/gtk-2.0/brown_bg1.png,
   borders don't fit within the image

   (emacs-gtk:17705): GdkPixbuf-CRITICAL **: file gdk-pixbuf.c: line 309 
(gdk_pixbuf_get_n_channels): assertion `pixbuf != NULL' failed

   ...lots more of the same deleted...


I'm not sure why it has a problem, as other GTK 2.0 apps I have seem to
function correctly (at least, gnome-terminal, and gtk-demo) and display
scrollbars/menus fine.

I do note, however, that other GTK apps don't seem to use libpng,
whereas emacs does, so perhaps there's a conflict there.

Here's some more info as attachments:


Output of emacs `configure --with-x-toolkit=gtk':

,emacs-config
Description: output of emacs `configure --with-x-toolkit=gtk'

Emacs ldd output:

,emacs-gtk-ldd
Description: emacs ldd output

gnome-terminal ldd output:

,gnome-terminal-ldd
Description: gnome-terminal ldd output

PNG file mentioned in above error message:

brown_bg1.png
Description: Theme PNG file that emacs GTK can't use

-Miles
-- 
"1971 pickup truck; will trade for guns"