Please describe the problem:
I tries to compile gnome-panel-2.16.0 with gcc-3.4.6 on slackware-current
(Linux 2.6.17 i386) platform. Compilations stops on:

make[3]: Entering directory `/usr/local/src/gnome-panel-2.16.0/applets/clock'
if i486-slackware-linux-gcc -DHAVE_CONFIG_H -I. -I. -I../.. -I./../../libpanel-applet -I../../libpanel-applet   -Wall -Wmissing-prototypes  -DORBIT2=1 -pthread -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/libgnomeui-2.0 -I/usr/include/libgnome-2.0 -I/usr/include/libgnomecanvas-2.0 -I/usr/include/libart-2.0 -I/usr/include/gconf/2 -I/usr/include/libbonoboui-2.0 -I/usr/include/gnome-vfs-2.0 -I/usr/lib/gnome-vfs-2.0/include -I/opt/gnome2/include/gnome-keyring-1 -I/usr/include/orbit-2.0 -I/usr/include/libbonobo-2.0 -I/usr/include/bonobo-activation-2.0 -I/usr/X11R6/include -I/usr/include/freetype2 -I/usr/include/libxml2 -I/opt/gnome2/include/evolution-data-server-1.4   -DDATADIR=\""/opt/gnome2/share"\" -DLIBDIR=\""/opt/gnome2/lib"\" -DSYSCONFDIR=\""/etc"\" -DPREFIX=\""/opt/gnome2"\" -DGNOMELOCALEDIR=\""/opt/gnome2/share/locale"\"     -O2 -MT clock_applet-calendar-client.o -MD -MP -MF ".deps/clock_applet-calendar-client.Tpo" -c -o clock_applet-calendar-client.o `test -f 'calendar-client.c' || echo './'`calendar-client.c; \
        then mv -f ".deps/clock_applet-calendar-client.Tpo" ".deps/clock_applet-calendar-client.Po"; else rm -f ".deps/clock_applet-calendar-client.Tpo"; exit 1; fi
calendar-client.c: In function `calendar_client_handle_objects_removed':
calendar-client.c:1340: error: `ECalComponentId' undeclared (first use in this function)
calendar-client.c:1340: error: (Each undeclared identifier is reported only once
calendar-client.c:1340: error: for each function it appears in.)
calendar-client.c:1340: error: `id' undeclared (first use in this function)
make[3]: *** [clock_applet-calendar-client.o] Ошибка 1
make[3]: Leaving directory `/usr/local/src/gnome-panel-2.16.0/applets/clock'
make[2]: *** [all-recursive] Ошибка 1
make[2]: Leaving directory `/usr/local/src/gnome-panel-2.16.0/applets'
make[1]: *** [all-recursive] Ошибка 1
make[1]: Leaving directory `/usr/local/src/gnome-panel-2.16.0'
make: *** [all] Ошибка 2


Steps to reproduce:
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Actual results:


Expected results:


Does this happen every time?


Other information: