MC60 I2C problem with the multi-slave

and another thing, when we tried speed up the bus to 1Mhz, we were surprised!
because we have a guest on our communication! look up at the picture

the second part shown in red is our request, it communicates with 1 Mhz but the first part shown in the purple is guest part and communicates with a different speed :confused:
why do we have this part?