Hi Jim,
I have done what you are describing, only with ZD3000. There are several steps involved in this.
1. Factory reset your ZF7982 (hard reset button on your device or SSH in and use "set factory" and then "reboot" commands)
2. Let them connect to the ZD1100. It will automatically downgrade the image.
Try the above. If the ZD100 is not recognizing the WAPs, then check the standalone Firmware on the WAPs. There are 2 versions out there: 100 and 104. Version 100 works with ZD1100 for sure. Version 104 is needed to associate to vSZ, but should work with ZD1100 also.
Best,
Alex