I think you are using this: http://archive.gp2x.de/cgi-bin/cfiles.cgi?0,0,0,0,6,2235 instead of the gmenu2x.
First you need to load the drivers (if you are not sure, load them all) by running z_load_all.gpe. Then connect your webcam. Then you launch of the programs.
If this doesn't work, you...