HOWEVER, I do recognize the code 4. In fact, it is so common of a
question that it is specifically listed in the PPP-FAQ document.
It is called RECEIVER OVERRUN.
Ditch those !@#$% IDE drives or live with the occasional tossing of
the UART data.
If you have IDE drives, try looking at the man page for hdparm, and the
-u option.
- Ted