I was running my demo in a debuger but I didn't tell it to use the debug version of ode.lib. Now I do. In ode-0.5/ode/src/lcp.cpp line number 1169: dReal wfk = delta_w[findex[k]]; It happens only rarely. Pawel S --- Jon Watte <hplus-ode at mindcontrol.org> skrev: > > Use a debugger. > > / h+