Entire system freezes


This is my first posting to this newsgroup, so please forgive me if this is
something common or something I should have found in the QNX documentation.

I have a PC on which I have installed QNX 4.25H. nettrap query gives the
following result:

Net.ether905 -p0 -l1 &

To start the networking, in the sysinit file I use:
Net -T&
Net.ether905 -p0 -l1&
netmap -f
nameloc &

Net.ether905 is version 4.24D. This PC is working flawlessly when it is in
my office connected to the same 3Com Office Connect hub as the other two QNX
machines (also 4.25H) I’m running. But, when I move this first machine to a
lab in another building, I get problems. The lab is on another part of our
network, this is the only explanation I can think of why suddenly the QNX PC
starts “freezing”. This can happen after 5 minutes or 20 minutes. By
freezing I mean it is completely dead. In Photon the mouse pointer stops
responding, but all windows remain and Photon does not shutdown. If I log in
without starting Photon, the machine will evetually get stuck in the login
shell, the cursor keeps blinking but the keyboard is dead. I can’t ping the
machine or get any response over the network. traceinfo doesn’t give any
clues about if something crashed. Any ideas?

Thanks in advance,
P-O Håkansson