I'm sorry, I cannot reproduce the error. Here is the test case I used to test it. In order for us to analyze the problem, we'll need to see complete, compilable test case which reproduces the problem, as George indicates.
main.h: used yours verbatim
main.c:
#include <stdio.h> #include "main.h" MainInt_t MainInt; int main(void) { printf("%p\n", &MainInt); }