Hi, i have a little prblem with navigation in 3D window with my spacenavigator

My units are mm and when i start to model something small, navigation in 3d window works great (when i create something small, like little speakres 25x10x10 cm)
But when i start to draw door (which is bigger, 140x220 cm) Then i start having problems with zoom in 3d. Its not complex model, just outline of door (8 lines :)), so it is not complex and havy model. It become very very slow to zoom in and out. It works great in other views but in 3d is too slow. Only zoom is 2 slow other movement like tilt, rotate works flawlessly
I open at the same time archicad and it navigates great there no matter what i do. I tryed everything but problems persist.

If i put zoom speed 20 then it works great in 3d but in other views is too FAST !

my 3dconnexion drivers are
relese version 3.11.3
driver version 6.11.1
firmware version 4.04
Spacenavigator
win 7 64 bit
In other aplications i dont have problems
thx

i just discover that if i put my model units from mm to m then zooming is ok, cos my model is scaled down.