Guillaume:
Your machine is not spinning the wrong way; Kenwoods are designed so that the mixer arm (the part the attachments fit into) spins anti-clockwise, and so that the attachments themselves spin clockwise.  When no attachment is fitted, it can be confusing to see the arm spin anti-clockwise, because one is accustomed to seeing the attachments spin the other way 'round.
Your machine is fine.  If you have any more questions about your machine, I suggest going to www.kenwood.co.uk and contacting Kenwood directly, as they can help you.
                
 Mixerhead
                
 February 2006