network issue

I am experiencing really strange behaviour with my QNX box.
When I put this QNX box in the network, it can’t ping gateway or communicate with anything until I unplug the network cable and plug this same network cable to windows xp box use it for few sec (like surf internet), and unplug this cable and plug it back into QNX box, then strange enough, QNX box now can surf the internet and ping other devices. But if I reboot QNX box, it’s back to not communicating?

This is the case for both static and DHCP mode. Maybe related to ARP?
Any idea?

thanks

Maybe it’s a problem with negotication of network speed. I have seen some combination of switches and NIC that dont’ work to well at startup.

What does nicinfo shows when it work and went it doesn’t work?

I resolved this problem by placing a router between my qnx box and the local network. Have the router do all the negotiation with switches. I can’t get the nicinfo right now, but if the problem is indeed with NIC negotiation what can be done? I did try 2 different PCI network card but the results were the same.