Touch the leads of the DMM together, 90% of DMMs won't read perfect resistance. If you touch the leads and it reads 0.5 like mine does, then subtract 0.5 from the final value.
As for the 0.01 issue, it sounds to me like the batteries in your DMM are low, but you seemed to have disproved that when you tried two different meters and since you are getting a realistic reading when directly connected to the subs.