tip doesn't always delete its lock files

[Ken Spagnolo]

I have tip configured to use ttyi07 to get somewhere.  While in use,
/usr/spool/locks/LCK..ttyi07 exists, which should be deleted when tip
is exited.  However, the lock file only gets deleted if the user is
in the daemon group!  Wierder still is that the non daemon group user
has no problem deleting the lock manually after exiting tip.  Can
anyone explain this?  Some relevant facts:

/usr/bin/tip     -  mode = ---s--s--x, owner = UUCP, group = daemon
/usr/spool/locks -  mode = -rwxrwxrwx, owner = UUCP, group = daemon

Thanx.

-- 
Ken Spagnolo - Systems Programmer, Postmaster, Usenet Administrator, etc.
   Computer Centre, Massey University, Palmerston North, New Zealand
K.Spagnolo at massey.ac.nz  Phone: +64-63-69099 x8587  New Zealand = GMT+12