Ok this is what I've done...
I have unistalled my video drivers (GeForce 9500 GT).
Ok its an oldy video card but with up to date support for windows 7 x64!
With no drivers, Windows detects my Video Card and use a Windows Drivers for my video card.
I open Sonar and same problem.
Then I downloaded the last video driver, installed it.
I open Sonar and same problem.
1 click in zoom and sonar exists suddenly!
Then I made a last proove, I open another project!
And have no problem zooming all the way in and out!
It seems like this issue occurs with my active project!
Any ideas now!?