you have some left over files from before would be my guess and a clean install should fix it
as for lbs to kgs its about 1/2 so 5400 lb = 2449.4 kg
a character with 8 str [the min allowed] gets 80kg total carry and starts around 50kg so has about 30kg of gear before she can't fight at peak [can still move but takes a penalty to skills and stats]
if the opening armour is light then it should = 3.5kg ... i think medium is around 4
