Good to hear that.
Listen, are you using MS Access as a front end? Please let me know, because there are a lot of ways that you can configure security a lot easier with MS Access front ends.
It is best to use Windows Authenthication because users do not have to use a user name and a password (users get tired of entering a password and username)
the reason I use windows authentication is, I will not nescesarily stay with a company forever, and with that security, a user can be trained to manage security when a new user comes into the company or an old user gets the ax.
Also it is a lot more secure because user think of a username and password as THE username for THE database. they share it with anyone and there goes your security.
Yes, I have had impossible users.