Cannot change Com3 settings at command prompt

System is XP Pro.
PC has (4) com ports.  1 & 2 are the standard integrated on mother board.
3 & 4 are via a PCI communications add in board.

Windows recognizes all 4 ports fine and I can change settings accordingly.

However, I have  (4) barcode printers that use the command prompt
PRINT function.  I can change Com ports 1 & 2 via the MODE command
at the C:> but cannot change ports 3 & 4.

When I issue the following:

mode com3: baud=9600 parity=e data=7 stop=1 xon=on

the response is displayed as:
com3   baud=1200
           parity=8
           data=1
           stop=1
          xon=off

Again, I can change ports 1 & 2 fine, but not 3 & 4.
Windows device manager shows no conflicts.

The main difference I see in the device manager is that
ports 1 & 2 show up as standard ports while 3 & 4 show
up as PCI.

Any thoughts?   Thanks,