[ODE] Car Sim Steering Causing Instability

[smythst]

I'm encountering a bit of a strange problem. I've just gotten my car sim's 
steering to work (ish), I'm using the same system as test_buggy.cpp, only I'm 
using a 4 wheeled vehicle.

Problem is, once the car turns 180deg, the buggy flips over and starts 
cartwheeling and the sim explodes. I can't track down why this is happening, 
there are no extra forces being added upon steering, and I'm only using 
surface.mu for the contacts. Anyone got any ideas what ould be wrong? I won't 
paste my code in  below as it's pretty long but if anyone wants a look at it, 
email me and I'll forward it to you directly.

Thanks.