i take a second fez cerb 40 ii and i reflash the loader. It was in 4.2 and i put the 4.3.
So in the first use, no problem, but when i put for the second time the program, i have the same exeption.
And, when i put your code, 1st time no problem, but i have exeption in 2nd time.
code (for your test) it"s just :
public class Program
public static void Main()
Watchdog.Enable(1000 * 15);