array index type of signed int

int array[ 0] _at_ 0x7600; //xdata
unsigned char index = 0; //xdata

printf("%d", &array[ index]);
printf("%d", &array[(unsigned char)(index - 1)]); //what is wrong?

// Result:
// 30208 --> 0x7600 (correct)
// 30206 --> 0x75FE == array[ -1] incorrect, // expected array[255] @ 0x77FE