508d problems

Is any one having a strange problem with 508d's? Between a few weeks and a few months after installation we get random FALSE warn a ways every couple of minutes. Even when paired with other brands besides DEI so the problem appears to be the 508d. I even rewired one on a BMW two weeks ago and drew power and ground from the car rather than the MUX port to "stabilise" it, yet 12 hours later.... I can't see it as a faulty batch, this is on units up to 4 months old and we install about 10 per week, trouble is this isn't a "one off", too many incidents on different vehicles.

I have only done 2 this year and both are presumably still out working fine. Fingers crossed To master and control electricity is perfection. *evil laugh*