I took a little video (sorry for darkness/quality) but shows the idea anyways. At start all esc leds are on even the switch is off.. Tho this happened earlier too and it was working.
When lift the car up on the video, I can get to higher rpm and then it works (like said on last posts too). On the ground you can see the buggy bugging. :)
http://www.youtube.com/watch?v=QBSWLftBrhs