Please check my post in the HW Settings thread, (link below) with my settings used and the problems I had running my brand new Xerun 60A Ver2.1 on the track this past saturday.

I have the another Xerun 60A Ver2.1
ESC in my 10.5 car with a HW motor and it runs perfectly.

On a side note...
I am thinking it might be the morotr, as it is a pretty old and tired Team Wave 13.5 motor, so possibly it is causing the problem.
I have a brand new Novak Ballistic 13.5 motor to try, and was wondering what settings I should change on my ESC to allow for the higher internal timing of the Novak motor.
My current settings for the TW motor are in the link below.

http://www.rctech.net/forum/8942483-post82.html

Thx for looking.