Theta/ Pioneer Elite issues, help

I own a Pioneer Elite VSX-52TX home theater receiver and it is currently being utilized with an Acurus ACD-11 CD player and a Theta DS Pro Basic II DAC. Having just added the DAC I am having issues. The 'over' light on the pioneer, (indicating that the analog signal is too hot), keeps flashing when playing certain cd's. I have read the pioneer manual and it states to use the 'att' or attuneator button to reduce the signal of an analog source. This being done the majority of cd's play without the 'over' light rearing its ugly head, but not with all. Several cd's seem to trigger the 'over' light and I am concerned that I may do damage to something? This is my first DAC so any assistance would be great, maybe I am missing something here??? Note: the Acurus run directly to the pioneer either in digital or analog does not induce the 'over' light to come on, so I am thinking the issue is with the Theta, but I am not sure???