I have checked all normal hints to sort this, related to personal firewalls, services enabled or disabled on the LAN interface for the qtek etc etc. The funny thing is that it works the first time but not then. When it is not working, a soft reset of the pda makes it work again. I don't have to do anything on the laptop to make it work.
Anyone who have any hints for me where to look? The Microsoft KB haven't helped me so far.