Passwords are case senstive. Have you checked that possible issue? (Maybe passwords were defined while caps lock was down and you are entering the passwords as lower case now...?)
Hey Phil, Ya unfortunately i have tried the case sensitivity issue and there is no problem with this. I don't believe there is any problem with the actual input of the username or password because of the "The account and password you entered cannot be used to access this file. Please try again." error dialog box that pops up when i try access the database...it just seems like a weird error, not the common "Either the Username or password is incorrect" dialog.
Does this file access other database files? Might the current account/password not match the account/password in another file that it is trying to open?
Is there any script running that might be displaying this message in a custom dialog?