The only advice I have is to make sure you screw the coil heads in snug. Make sure the 510 pin on the atty and 510 connector on the mod are clean. I use a q-tip moistened with rubbing alcohol to clean, then use the dry end to wipe/dry with. Give it a few minutes to air dry and your good to go. If you really think your mods are reading the resistance incorrectly, the only advice is to check them (the coils/heads) with a DMM or ohm checker.
Cheers,
Steve
Cheers,
Steve