I'm really sorry that I haven't given enough information,
I've tested the DUE with my other projects, which doesnt use the Keypad_I2C library, and they seem to work fine.
I also tried using the Wire library with LiquidCrystal_I2C library, and I got the connection with the I2C chip, and everything works fine.
The problem comes on when I include the library Keypad_I2C.h, I don't need to use it elsewere, just incluing it in the code brings up the problem