Arf1410
Are you referring to a physical COM Port or
a USB to serial device?
I do not have much confidence in the CM15a
+ AHP, and yes they do leave that annoying
X10net running even after uninstall, but I
do not think it should affect your other
port settings.
Many USB enable peripherals devices add a
virtual COM driver, win XP can have up to
256 virtual COM ports, what is probably
happening, windows mapped the CM15a on the
same COM port number as your other devices,
you can easily change that: go to System
property, Ports (Com & Parallel) select
port settings _> advanced and make sure
that the CM15a and your other serial device
are set to different COM numbers.
Before you make the changes both devices
need to be plugged in.