I have two applications, both written in Delpgi 2.01 using BDE 4.01.
Each accesses an Interbase database. App 1 uses no local tables and
has one form. App 2 uses local Paradox tables and uses dozens of
forms.

When App 1 is running on a workstation and has the Interbase database
open and a query active, App 2 crashes with an access violation when
attempting to post to a local Paradox table via a TTable object. This
is while inserting a new record. App 2 also has the same Interbase
database open and has several Tqeuries active to it.

App 2 does not crash unless App 1 is also running on the same PC.

Anyone ever see anything like this before? Any ideas of where to begin
debugging it?

Try setting the session netfile path for paradox net files to something
other than the default (exe startup directory), tends to be collision
central for some applicaions.

If you run cached updates or local tables that you want isolated, move the
path to the users C: drive before connecting the database component.

ie.
forcedirectories(C:\temp);
Session.netfiledir := 'C:\temp';
Database.connect := true;