Thank you to Wally at 3Com support to this fix.
We have found a workaround for the issue of the 3C10400B continuing to reboot after upgrading to 6.5.18.
The workaround involves renaming a file.
Here are the directions:
1. ftp into the NBX using the administrator password 2. cd /htfs0/R6_5_18/BootLoaders/ATA_g3 3. In this folder, you will see a file called "revision.dat" (lower case r). This file should be named "Revision.dat" (Upper case R).
4. do a "get revision.dat" to pull the file off and place on your PC 5. on your PC, rename the file to "Revision.dat"
6. do a "put Revision.dat"
7. next, since you do not need the "revision.dat" file, do a dele revision.dat. This will leave only the upper case "Revision.dat" file 8.That's it !!! The 3C10400B will now reboot.