That would be symptomatic of the compass having to put in too large of correction to be accurate. Either there is something in the airplane interfering with the compass, or the ADAHRs is bad. You may want to first check by placing a "boy scout" compass on top of the ADAHRs and looking at what it says when your plane is pointed N-E-S-W (on the ground). Is it anywhere near the right heading? If not, I would look to see what could be effecting it. If it is close, then you should probably contact us at have the ADAHRS checked.