@guy1
Then are you looking at your model's scale inside of your 3d program before you are exporting it as .x?
Like i said in your modeling program a cell or square that makes up one room block in fpscreator is 100x,100y,100z in a modeling program, a floor in a modeling program is 100x,100y,2.5z so the height of your object from the floor to a ceiling would be 97.5 on the z axis of your modeling program to have it scaled from floor to ceiling so check the scales of your model in your modeling program before you export your .x file. If your model was let's say a coke can, then your sizeing for that model would be around, 3x,3y,15z in your modeling program, problem is you would not see that model or it would be extreamly small in fpscreator so, in your modeling program up the scale sizes to something like 50x,50y,62z keep them even so your shape doesn't get distorted, then your model will be larger in fpscreator about half the size of a room from wall to wall and ceiling to floor, then use the scale = line in your fpe to reduce the object down.
Edited Actually the 97.5 isn't the correct size from floor to ceiling when its from floor to top of a side wall in a segment i forgot to take into condsideration that when you place you ceiling it is droped into the lower level by about 1.5 so that would make ceiling to floor around 96.