There are two types of oscillators for the ATMEL used on the ESC. External Crystal Oscillator Resonator and internal which use a capacitor.
The external is preferred because the throttle range is best kept over time, the internal has a tendency to change.
Therefore you need to recalibrate the external version more often. (You find this info also on SimonK forums)
For next time you can find here if the ESC has a External oscillator:https://docs.google.com/spreadsheet/ccc ... ZRlE#gid=0
Always calibrate the ESC's after programming. My experience is that due to component differences the range can be different.
Calibrating (yes do the Ext. and Int. oscillator version!):
ALWAYS TAKE YOU PROPS OFF!!!!!
Use a normal receiver, connect the ESC to the throttle channel.
> Receiver on.
> Set full throttle stick
> Power the ESC (if the ESC is not powering the receiver add power to the receiver first before you power the ESC)
> Wait for the beep
> Pull stick back to full-low-throttle
> Wait for the Beep(s)
Do this for all the ESC, better to do them all because of the possible temp differences between calibration.
(again most of the time not noticeable but I had the experience that the throttle range was different. I did the throttle a week later).