PPP poff script "meta/recipes-connectivity/ppp/ppp-2.4.5/poff" is using killall program. It is not working without include psmisc into image.
Busybox builds a killall binary in its default configration? Are you using the standard busybox config?
There is no busybox in image (gumstix-console-image). I post bug in wrong place, sorry and thanks.