ECN Forum Forums Code Related Discussion NEC & other Code issues Mixing DC with AC conductors?

I wonder wether there are some practical issues at play as well.Such as some current being imposed (through induction)on the DC circuit causing havoc with the circuits on the DC power run.
To be safe i would go with the rule of thumb of not combining one with the other.
Along the lines of even if it is permissable -should it really be done??