hi michinyon,
Thanks for the reply, yes it has been configured... i think the problem was caused by the built-in pullup resistors by the arduino due on pins 20,21. As far as the schematic of Due goes, i found out that it has 1.5k built-in pullup resistors attached to the voltage regulator(3.3V) connected to 20,21. I'm not sure if the pull up keeps affecting my readings in DUE since UNO does not have a pull up resistor by default on pins A4,A5.
I've also tested using pins SCL1 and SDA1 (2nd I2C of due without pull ups) on DUE but it wont detect the mma7455L without an external pull up.
so far with the built-in pullups of DUE i somehow get fluctuating readings. while on UNO i get a stable reading. forgive me if i ask such questions. but should the pullups be giving 2.4V based on the module's specs "low voltage operation: 2.4V3.6V" ? currently the builtin 1.5k pullups are giving me a default of 3.3V.