Root Directory Mis-Permissioned

Tue Mar 5 06:27:06 AEST 1991

It has happened twice now that users have been unable to login to my DS5000
running Ultrix 4.1.  When I log in as root and try to "su" to a user, I get the
message "No shell."  Checking around, I find that the root directory has
permissions "rw-rw-rw-"!  I change to "rwxr-xr-x" and everything returns to
normal.

Any idea how root is becoming mis-permissioned?
-- Joshua Yeidel