I have some more info on this problem. In alert log I get ORA-00600 internal error code arguments [16306] [3221749815]
According to oracle this is due to a known bug in Oracle 8i, bug # 853642, which limits the number of defined network interfaces to 10, with the suggested workround of reducing the number of network interfaces to 10 or less.
This solution does not seem to apply in my case as there are only two network interfaces defined, loopback (lo0) and one ethernet (hme0).
Anyone else encountered this problem?
Thanks
Richard