Apple IIe + Modem (Sportster 14.4) ?

[kellihanb@aol.comDelete (KellihanB)]

Hello,

   I finally got a Super Serial Card for my Apple IIe.  I also got a USRobotics
Sportster 14,400 Fax Modem.  Unfortunately I've been having some problems
getting them to work.
  Using  Apple Access II, I wasn't able to get it to automatically dial
anything.  It says the modem isn't responding.  However, by going into terminal
mode, and typing AT commands blindly, the modem will respond correctly and even
make a connection.  Unfortunately this program has no facility for VT100 or
ANSI emulation and can't even do XModem transfers...
  So I got myself a copy of ZLINK.  The disk boots and I start ZLink.  It hangs
after you select ZLINK.SYSTEM from the ProDOS start up.  Now, on a hunch, I
tried unplugging the modem.  ZLINK works fine.  Plugging the modem in doesn't
affect ZLINK until you type a key.  It locks up.  Unplugging the modem will get
ZLINK going again...  
   What's wrong?  Does anyone know what's causing this behavior?

Thanks,
Bret