Home from work, so now I can check out your game. Okay here is your situation.
First, Stonehenge always takes 120 hammers to build on normal speed, no matter whether you are an industrious leader or not. You are playing Marathon Speed in both of these save games, so everything is multiplied by 3 - therefore 360 hammers to build stonehenge.
Now, the industrious trait does not cut the number of hammers required to build a wonder in half, it multiplies the number of hammers your cities produce by 50%. That means that if your city was normally producing 2 hammers, if you decide to build a wonder you will produce 3 hammers. (2 * .5 = 1, plus the original 2 = 3)
Your cities, in both of these saves are at population 1, so each can only work 1 additional tile besides the city square. In both games the central city tile is only producing 1 hammer. In one of the games, it is working a rice tile (3 food, 0 hammers) and in the other a corn tile (3 food, 0 hammers). that means your total production for the city is only 1 hammer. 1 hammer * .5 = .5 hammers, which is rounded down to 0. That means 1 total hammers, and therefore 360 turns to produce stonehenge (Assuming the city never grows).
You got different numbers of turns in your map regenerate, because you got a start with more hammers as the default. Move that tile that is being worked from the corn to the forest, and you will see your turns decrease. However, it will always take 360 hammers to build stonehenge on marathon speed.
This issue comes up for many traits as well as abilities provided by buildings, promotions, etc. Civ IV uses a system of multipliers, it never changes the base values - just allows traits and abilities to adjust via multipliers.