The NIC driver is being installed via a batch file and the unattend file. Win 7 did not have any nic driver for it *E6510), so I copied one from Dell in the image job itself, and install as noted above. The driver does not get changed. One of the driver jobs does reinstall it using the same switches, though in this case it is not necessary.
The problem occurs even when no drivers are installed or changed, but when repeated reboots occur. I can recreate it with a test job I made for this purpose that sends 10-12 reboots in a row after re-joining it and doing the required reboot.
The rejoining can be via a job or manually. The error occurs with the multiple reboots.