INIT spawns gettys repeatedly - why?

[HCART at vax.oxford.ac.uk]

    Following a recent crash, the performance of our 3130 has
fallen significantly.  Output from  ps aux  shows that INIT
is spawning a getty on serial line 2, on which we have an ascii
terminal.  After a few seconds, a  login  process appears for this
line, even though no one is using the terminal.  A short while
later, a new getty appears and the cycle repeats endlessly.

    I have tried editing /etc/inittab to remove the entry for
serial line 2, and everything returns to normal, as one would expect.

    The unwanted processes are spawned at such a rate (about one
every 10 seconds) that the reduction in performance is noticeable.
Anyone have any suggestions as to the probable cause of this
difficulty and how we can resolve it while still using the
serial line?

    Any help much appreciated.

    Hugh Cartwright,  Physical Chemistry,  Oxford.