Sorry for a late reply.
When I sent you an reply earlier, I did some testing using v6.5, and could reproduce same issue you reported, but I did not realized that I have the preference 'Show Logon Dialog on startup" set to OFF. I have removed my last note as i could confirm that it worked as expected.
Could you please check your preferences and make sure the option is selected as attached screen shot. (Preference window can be open from main menu View->Preferences). When having it on, you should get the logon window everytime you try to load the sql file from windows explorer. I have checked and could confirm that it worked as expected, ie. I could see the log on windows everytime.
Please let us know how you go.
Thanks and regards,
Message was edited by: bruceduong