intermittend problem with network interface card

the nic shows up properly in the TCP/IP config - phlip
i get no error messages during boot or launching io-net
can successfully ping my own IP adress
cannot ping or ping -n other IP adresses (ping: sendto: host is down)

i connect my fluke lanmeter directly (no hubs etc) and run a nic test :
everything ‘active’, ‘normal’, …, i receive arp frames and even the correct mac adress.

the output of arp -a takes 5 seconds or more, all ‘incomplete’ (normally this takes a fraction of a second in my machine)

now i use the nic in my WINDOWS partition, and again in the QNX partition, and eventually, not everytime it works correctly in QNX again.

qnx : 6.2.1
nic : pcmcia 3com etherlink 3C589D (, various cards tried so far

ANY IDEAS HOWTO make the nic work ANY time i use QNX ?

regards Helge