panel make problems.

[gardnerj]

For some reason I've been getting this for days when making what I pull
off CVS:
xfce_support.c: In function `real_exec_cmd':
xfce_support.c:816: warning: implicit declaration of function
`gdk_display_get_default_screen' xfce_support.c:816: warning: implicit
declaration of function `gdk_display_get_default' xfce_support.c:816:
warning: passing arg 1 of `add_startup_timeout' makes pointer from integer
without a cast

Followed a little later by:

xfce4_panel-xfce_support.o: In function `real_exec_cmd':
/home/gardnerj/src/xfce-devel/xfce4/panel/xfce_support.c:816: undefined
reference to
`gdk_display_get_default'/home/gardnerj/src/xfce-devel/xfce4/panel/xfce_s
upport.c:816: undefined reference to `gdk_display_get_default_screen'
collect2: ld returned 1 exit status make[2]: *** [xfce4-panel] Error 1
make[2]: Leaving directory `/home/gardnerj/src/xfce-devel/xfce4/panel'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/home/gardnerj/src/xfce-devel/xfce4'
make: *** [all] Error 2
[gardnerj at localhost xfce4]$ 

What could be happening? What am I missing?

Thanks,
Jonathan