This part of your original post (referenced above) confused me from the get-go. Performing a firmware update on the DCS-932L will not impact the stored username/password combinations that you've previously defined. That said, there are only three ways the default password (blank field) can be re-instated: (1) a new password was never selected when you originally configured the DCS-932L out-of-the-box; (2) you reset the DCS-932L to the factory default settings; (3) you manually changed the password back to a blank field.
My rebuttal for each item:
(1): I selected a new password for each right after I installed them last April.
(2): I haven't done this
(3): I didn't do this either
I had the password set before the required firmware update and afterwards it went back to the default. It didn't change any of my other settings. I know it doesn't sound right but I promise you it's what happened. I even remember wondering why my password wasn't working when I tried to log in after the firmware update. I didn't think much of it and left it alone.
If it makes any difference, I updated the firmware from the house from the mydlink site. Maybe that's why it got changed.
Either way my network and cameras are locked down now. All passwords have been changed and most now use 10 digit generated passwords to be more secure. We'll see what happens from here.
Thanks for all the help everyone, I'll update later if this continues to happen.