XRAY - Model racing cars

I have recently moved to running an x-ray t2, and it is completely different to drive, it is so smooth and responsive. The only thing i have broken is the stub axle on the rear driveshaft. I clipped a corner and the wheel fell off and it had snapped where the drive pin goes through. Has anyone else had it happen as i don`t know if it is the way i drove it or if anyone can shed some light as to why it could have happened. I have ordered some new ones but if it the way i built it then i need to be adjusting it somewhere so it doesn`t happen again. It has had two days of racing which is why i thought it could have been how i built it. Great car otherwise.