for example:  Unit Weight is .7921 lbs.  for a dozen toothbrushes.  However, a customer ordered 20 eaches, which we have got the pricing and invoice UOM's correctly for display on the customer invoice.

But the weight is not calculating based on the different UOM settings, which are correct.  So it is saying that 20 toothbrushes weighs 15.54 lbs, which is crazy wrong.

Also, when the system picks up the weight of the order through the shipping system, because it is not converting here, it is rating the shipment at 15lbs instead of at 1.32 lbs.

Am I missing something?

we don't know how you setup your conversions.  You main UOM should be EA with a conversion of 1.  so then the unit weight would be 0.7921/12 if that's the weight for the dozen.   you could have a UOM of "DOZ" with a conversion of 12 so then when you type up 12, it should equal 0.7921

Like Mike said, the unit weight is the weight of the the Stocking Unit of Measure.  If your Stocking UOM is dozen then the Each UOM should have a conversion factor of 1/12 or .083333.  

Another way of doing this is making your stocking UOM Each with a unit weight of 0.066008. 

Dana