Disk or Network Error: sporadic on networked Access db

Disk or Network Error on an Access networked multi-user database-level security database.
--Diagnosis---------------------------
All users were able to connect to the Access database initially, but then some would sporadically receive "Disk or Network Error" and have to reestablish their network connection to the database. Since some users received this error and others did not, we thought it was the local computer/NIC/Cable, not the network. Not so! Turns out that people coming in early in the day got NAT (see below) but the NAT translations were gone by the time later users logged in do they got PAT (see below). The later (& latter) users had the problem.
--Here's the technical low-down: --------------------
It was related to an address translation (AT) technique used when accessing servers outside a firewall. There were two choices: P (Port) AT and N (network) AT. The NAT worked fine, but there were not enough to go around. The default was PAT which caused the "Disk or Network Error" message. Our solution was to move the database inside their firewall.
--Commentary---------------------------
I hope this helps someone else, because it
was a royal (*&^%@#^$@#!)_##$Q !!!!! to figure out.