Machinarium very slow

[at.choum]

Hi

I just install the game on my PC (Windows 7 pro 64 bits, NVidia 3D GC, Intel T94000, 4Go memory).
After 2 or 3 minutes, game is slow, very slow, it's impossibile to play . In the same time, sound is very bad.
And sometime, rarely , all work.

How can I make correction (perhaps on video cad). !!!!

Thank you
@choum

ADD
I saw http://machinarium.net/forum/index.php/topic,997.15.html
It seem to work in no full screen.