Vig, I don't have Firefox , chrome
I'll check the task manager tomorrow, good idea.
Vassago, my laptop has a fresh install of windows 7, and my pc a 8 month old install of vista.
I had to install 3ds max 9 for work, and that one does work withouth slowdowns, so I think it is max itself, 2009 version to be specific.
Thanks for your help, will let you know if I manage to fix this.