New IPaddress in spite of configured IP address

We have SUSE 10.2 which changes its IP address on start. Where would I look
for the config file which is doing this? The machine shows a configuration
in YAST Network that calls for a static ip number, and the prompt at the
point of login shows the computer's network name but as soon as I log in the
prompt changes to the fourth octet of the new address. Ifconfig shows that
the ip address is not the static address. What might cause this?
John