A strange problem has just occurred on one of our DECstation 5000's running ULTRIX 4.4 I can log on console as root I can su to non privileged account eg su davec I cannot su to root, operator or field (no messages or warnings - it just hangs indefinitely) Any Ideas? Dave. Dave Corsar The Highland Council, Glenurquhart Road, Inverness Scotland IV3 5NX 01463 702636