[ODE] vector has zero size

[Kurt Blackwell]

I'm running ODE through some paces, and I found that if I modify 
test_boxstack.cpp so that it drops objects from a height of 1000 it 
often gets stuck reporting "vector has zero size" in dNormalize4.  Heres 
the VC6 stack, should it give you some hints:


dNormalize4(float * 0x097cccc8) line 137
moveAndRotateBody(dxBody * 0x097ccc20, float 0.0500000) line 289 + 14 bytes
dInternalStepIsland_x2(dxWorld * 0x008545d0, dxBody * const * 
0x0923fd10, int 0x00000001, dxJoint * const * 0x0923fd00, int 
0x00000000, float 0.0500000) line 1027 + 45 bytes
dInternalStepIsland(dxWorld * 0x008545d0, dxBody * const * 0x0923fd10, 
int 0x00000001, dxJoint * const * 0x0923fd00, int 0x00000000, float 
0.0500000) line 1066 + 29 bytes
processIslands(dxWorld * 0x008545d0, float 0.0500000) line 177 + 29 bytes
dWorldStep(dxWorld * 0x008545d0, float 0.0500000) line 1256 + 13 bytes
simLoop(int 0x00000000) line 357 + 23 bytes
dsDrawFrame(int 0x00000160, int 0x00000120, dsFunctions * 0x0012feac, 
int 0x00000000) line 1088 + 21 bytes
renderingThread(void * 0x0012fd28) line 139 + 60 bytes


It seems to happen with boxes and cylinders, but I haven't got it to 
occur with spheres.  Any ideas?