OK, that's fine... but how are you connecting the amp to the output of the DAC??
I'm guessing you are using it either as a buffer stage or a non-inverting stage, so there should be negative feedback which will increase your ICMR. If this is what your doing then what you need to check is your ICMR+ and ICMR- values, which for your topology are:
ICMR+ = Vdd-VsgP3+VtN0
ICMR- = VdsatN2+VgsN0
What you need to do is set this values to the MAX and MIN output values of your DAC, that way you'll guarantee that the amp is not saturated.
Hope this helps,
diemilio