You probably have checked this already but have you tried calibrating without the servo? Also triple check that the ESC plug is in CH2 and facing the right direction.
According to this thread:
http://traxxas.com/forums/showthread...s-in-my-e-revo you need to max out your EPA's and if you haven't already use the CC Link to install a different version of the fw or at least reset the settings to default.