Can you try this sketch? and post its output?
#include "Wire.h"
#define addrs 0x78 // I2C bus address
void setup()
{
Wire.begin();
Serial.begin(9600);
}
void loop()
{
byte b;
Wire.beginTransmission(addrs);
Wire.write(1);
int x = Wire.endTransmission();
Serial.println();
Serial.println(x, DEC);
while(Wire.available())
{
b = Wire.read();
Serial.println(b, dec);
}
delay(1000);
}