"I put my mdw file in the shared directory, and added groups, users and permissions on both the front and back ends, but the Access logon dialog box (asking for my name and password) only comes up on my desk. Can anyone tell me what I'm doing wrong?"

1. You need to revoke all permissions for the Admin user.

2. You should add this to the command-line or shortcut:

/wrkgrp TheMDWFile.mdw

This eliminates the need to join/leave the workgroup before/after using the
app.