serial communication with processing in 115200 baud

9600 should be the best rate for arduino and processing to communicate,
the problem is my arduino is running at 115200 to communicate with other sensors,
now, when i read the data in processing (running in 115200),
sometimes the data is right but sometimes is wrong...
any solution?

the whole picture:
2 arduino slave connected to the master arduino via I2C,
each of them connected to a magnet sensor (running at 115200)

thanks!

build in some error detection, e.g. a CRC code after each data packet?

If you want your code reviewed, please post it (both processing & arduino)

9600 should be the best rate for arduino and processing to communicate,

Why? Faster is almost always better.

each of them connected to a magnet sensor (running at 115200)

A serial based magnet sensor?

What is the "master" Arduino doing? The rate that the slaves talk to the serial port has nothing to do with the rate that the slaves talk to the master over I2C.