I've been having the same trouble from -current from a week or two ago.
It doesn't always get the fifo overrun, just most of the time.
The most recent kernel I have that doesn't have this problem is from Nov. 3.

-Chuck

In message <199611201737.EAA09541@eterna.com.au>, matthew green writes:
> 
> i haven't played with this much yet -- my network link depends on it,
> and it 'works' on my ipx, but...
> 
> when i upgraded my kernel to 17th november sources, and rebooted, my
> ppp chat script failed like this:
> 
> Nov 19 20:15:43 splode chat[301]: send (ATZ^M)
> Nov 19 20:15:43 splode chat[301]: timeout set to 10 seconds
> Nov 19 20:15:43 splode chat[301]: expect (OK)
> Nov 19 20:15:44 splode /netbsd: zs0a: fifo overrun
> Nov 19 20:15:44 splode chat[301]: ATZ^M^M
> Nov 19 20:15:44 splode chat[301]: O
> Nov 19 20:15:53 splode chat[301]: alarm
> 
> it's as though the zs couldn't handle the 3 character reply (OK\n).
> 
> 
> i've not really looked beyond this, so i don't have more info.
> 
> does anyone else ?
> 
> 
> .mrg.