DE2 audio examples using DSP Builder

I am trying to put in a FIR filter between the adc out and dac in on the DE2 board and failing miserably. I am using the DE2 board with cyclone II EP2C35F672C6N fpga. I split the two channel data out of the adc out and filter each channel seperately. The filters are identical though. The passthrough from the filter modules ( i.e. when I pass the filter inputs straight to the output without filtering) the dac output is perfect but fails with the filtering process engaged.