try to fail gracefully when s <= 0
try to fail gracefully when s <= 0


git-svn-id: 051f6adb867ae8800663f9d761b7f383ac0911ea@259 685f7672-210f-0410-90b4-fe3ad19314fe

vancegroup-mirrors/open-dynamics-engine-svnmirror,vancegroup-mirrors/open-dynamics-engine-svnmirror,vancegroup-mirrors/open-dynamics-engine-svnmirror,vancegroup-mirrors/open-dynamics-engine-svnmirror,vancegroup-mirrors/open-dynamics-engine-svnmirror