Many people have problems with the scale on imported objects from AutoCad,

here is a brief description how to solve the problem:

When you are in a project, use the "Extract" function under "File".

Find your file,  change filetype to AutoCad Files and open it, a new window is opened, highlite the object (even if it´s invisible) by marking a rectangel around the middle of the window (left mouse button pressed down). When you have caught the object you get red tools, use the arrow and drag the object to a view in your project. (it can take some time depending of the size) With the object still selected, click on "Selected items" in the control window and change "Drawing unit" to something bigger.

Lasse Capture