Stock Revo's EVX-2 on fire

I was running stock e-Revo for some months now. Two weeks ago I have bought Lipo's, installed the Novak's LVC and all, and couldn't stop smiling (for 3 runs). The LVC was working fine, and considering it's only titans -the car had much better acceleration than with Nimh's, of course.
Two Days ago - I was at the track (just basing around). After about 10 minutes of bashing - the car stopped moving, steering servos were still responding. I went to see What was wrong:
The titans were warm, but not hot. The Evx-2 - the same.
I disconnected the battery connectors and connected them again - the Evx-2 went on, but only the steering servos were responding.
I thought maybe thats the Novak cutoff that wasn't good - but it seemed O.K. When I "programmed" the cutoff -it acted perfectly (red, green lights and all...).
I tried to disconnect and connect the batteries again - and PUFF! the Evx-2 smoked on me.
When I went home this is What I saw :


Does anybody know what was wrong here? Why did that happen? anyone had similar experience? Do you think it's related to the cutoff at all?
Please Help. I sent the EVX-2 to Traxxas, but do not want it to happen again with the one they will repair for me...