can not load png images

[fish <fish nccu edu tw>]

hi,

After my installations, I start gnome but I got the 
messages for "default set of icons not found,
please check your installation"

When I switch back to the console, the messages in the console says
"gdk_imlib ERROR: can't load image /usr/local/share/pixmaps/xxx.png"
These errors are the same as artilces post in "Thu, 4 Feb 1999 21:21:13  
I'm having PNG problems in RedHat 5.2 also".
My situations is the same as this,except that my platform is FreeBSD 3.1 release
What the probelms are ?

Thanks for your help !

fish