no jpg support in xfce 3.8.18 on mandrake 8.2?

[wolfgang]

i compiled and installed xfce-stable from cvs on mandrake 8.2
xfce is unable to use jpg files as desktop backgrounds error about invalid 
file type.

installed packages:
[root at rothut xfce-stable]# rpm -qa | grep gdk-pixbuf
gdk-pixbuf-loaders-0.16.0-1mdk
libgdk-pixbuf2-0.16.0-1mdk
libgdk-pixbuf-gnomecanvas1-0.16.0-1mdk
libgdk-pixbuf-xlib2-0.16.0-1mdk

i downloaded, compiled and installed gdk-pixbuf-0.9.0.tar.gz additionally, 
then recompiled and installed xfce, still jpg cannot be used, but there is no 
longer an error message, it simply doesnt work.

how can that be fixed?

regards,
wolfgang