construction quotas

[gabrib]

Hello, everyone. I recently use autocad mechanical 2009, and I have a problem: when I design the construction lines, I admit the quota, then I go to quota it the generated line and I realize that it is never correct, generally it is always poor of a few tenths of millimeter regarding what I typed, is it me wrong or is there any setting to set??? thanks for the attention.

 

[GiGa]

Did you check that the bird's all right?

 

[gabrib]

Could you give me some extra indication? Thank you.