I would take out the internal modem and set the external to use COM2.
COM3 and COM1 share the same interrupt, so basically when you set your
modem to COM3 you are going to have problems either with the modem or the
mouse or both. I think COM2 and COM4 may have the same interrupt, so
when you set your external modem to use COM4, you ran into a conflict
with the internal modem. So pull the internal modem and see if the
external then will work.
Juan
Juan Jewell The Sidwell Friends School
jewell@sidwell.edu Washington, DC
"Taking care of the little things takes care of the big things."
-Walt Hazzard