Sorry for not responding sooner as I just saw this post. Think the problem is code to compile correctly you have to use 1.5.6r2 or greater. Also, while their are 20 different libraries not all are used. Only the libraries that match the imu you specify in FreeIMU.h are loaded. unfortunately with all the changes the library compiles to about 10k more that Uno has if you are using that board. Mega works great. See the wiki on the github pages - should help in setting it up.