Sorry, its been too long since I have used FaxWorks. (I don't have it
loaded on this laptop that I've been using for some time now.)
Then something else is grabbing the COMM port and releasing it. Could be
a DOS or Win-OS2 session that is not completely closed, for instance.
Check settings in your other programs to see if they can set (aka
"forced) to release the port after they are done with it.
I used to use FaxWorks running in the background, so that it could
answer faxes, while still using other programs at the same time. So,
this sharing can be done!
Hopefully you'll here from somebody else using the same programs and
setup as you have.