io-net crash

I develop under QNX Neutrino 2.0C and I have trouble with io-net manager and
ttcpip, it’s crashes sometimes while working with a few tcp connection. The
io-net process crashes and there is such message:

Process 8201 (io-net) terminated SIGSEGV code=1 fltno=11
ip=b0352744( mapaddr=b0308744.

There is running httpd server and while any user from another station starts
loading web page within browser, there are a few tcp connections and
suddenly io-net process terminates. This never happens when station with web
browser and with neutrino is located in the same local network. While there
is few or more routers between them I have got such problem with io-net.

I have used ethernet snifer to analyze tcp frames and there is nothing
strange, tcp frames are ok, simply after some TCP SYN ACK frame there is TCP
ACK and this is the last frame, I think this is point of io-net crash.

Have you ever had similar problem with io-net and ttcpip? Please help if
anybody know it.