There's a helpful video by Fabio on how to use FreeIMU and callibrate it.
The thing you need to remember is to set the FreeIMU header file to use V3 if you are using one of the cheap devices found on ebay like GY85, this is the one with three separate chips, the FreeIMU v4 was different and so won't work. See the FreeIMU.h file for more information and to set your device by commenting/uncommenting the appropriate lines.
I don't think there's any difference in the 3200 and 3205 chips as far as this is concerned and mine seems to work fine.
Please note that callibration can be a bit tricky, the GUI sometimes fails a bit (it does say that it is alpha code so expect a few hiccups).