Hangup ignored--known problem?

[Robert L. Oliver]

We have an SCO Xenix 386 system with a multi-port async serial card.  It
has the annoying feature of ignoring hangups (loss of CD).  Thus, people
dialing in can be connected to an already logged-in session.

I was about to go into deeper investigation after a first glance at the
gettydefs and wiring appeared to show no obvious deficiencies.  I was suspecting
perhaps a bug in the driver with relationship to whatever brand of multi-port
card is installed (I don't know the brand at the moment).

But before I had the chance to look further, someone told me that this
was a KNOWN bug in Xenix.  

I find this amazing, if it's true.  And if it IS true, what does the civilized
world do about this?  Can't exactly use this sort of thing for any secure
dial-in.

Any info. would be appreciated. 
--
Robert Oliver			
Rabbit Software Corp.		(215) 647-0440
7 Great Valley Parkway East     robert at hutch.uucp
Malvern, PA  19355		...!uunet!cbmvax!hutch!robert