Do you have the serial script in your init scripts?
There is a file "rc.serial" in the documentation directory for the
setserial package:
setserial Version 2.15 (2-Nov-98)
Setserial is a program which allows you to look at and change various
attributes of a serial device, including its port, its IRQ, and other
serial port options.
Starting with Linux 0.99 pl10, only the COM1-4 ports are configured,
using the default IRQ of 4 and 3. So, if you have any other serial
ports provided by other boards (such as an AST Fourport), or if COM3-4
have been a non-standard IRQ so that you can use time simultaneously
with COM1-2, you *must* use this program in order to configure those
serial ports.
The simplest way to configure the serial ports is to copy the provided
rc.serial file to the appropriate /etc/rc.d directory. For example,
to install rc.serial on a RedHat system, copy rc.serial to
/etc/rc.d/init.d/serial, and then run the command "chkconfig -add
serial".
I would use the GUI script configuration tool, ksysv in KDE, to check
this, or to do it.
After you do this, your serial configuration will be saved when you
shutdown and restored when you reboot.
JRT