I downloaded the sample “Simple Notepad” database, dragged it to my databases folder and renamed it NOTEPAD in the finder. When I double-click on it, it does not open on the desktop. To open it, I have to then go to the dock and click the DT Pro icon. I have had this happen once or twice before, but the problem went away!? I thought it might be because I should not have renames the database in the finder, but rather in Database Properties dialog box, so I renamed it there also, but it still does not open until I go the the dock. Any ideas? Thanks.
Jerry, I don’t understand the problem. When you double-click on a DT Pro database in the Finder, it will either (a) launch DT Pro if not already open, and open as a database in DT Pro or (b) close and replace any other database that’s already open in DT Pro.
To view and use the database, DT Pro must be the frontmost application.
This morning, when I double-clicked the database in question to open it and DT simultaneously, both opened as expected. When I have another database open and double-click the database, it opens. When DT is open and no database is open, and I double-click on the database in question, it does not open. It is not hiding behind another window, and it is not minimized in the dock. In this case, to open it after I double-click it in the finder, I need to go to the dock and click the DT icon. This same behavior has happened a couple of times before with other databases, but in those instances the problem was corrected, though I don’t know how.
This idiosyncracy is not a big problem for me now that I am aware of it, but, if there is a simple fix, I would appreciate knowing. Maybe I should just trash the database, since it has little content at this time, and recreate it (after a I copy the contents, of course).
As a postscript, I changed the name of this database in the finder not in the Database Properties dialog box, whixh is what caused me to think it was a directory problem. I then changed the name in the dialog box, but the behavior persisted. What it the best policy for changing the name of a database—finder or dialog box? 
Hi, Jerry: I can’t replicate the behavior you describe, but don’t worry about it.
You should make one of your databases default. To do this, select File > Database Properties. Near the top of the Database Properties panel click to make this the default database. It’s important to have a database open whenever DT Pro launches, so that any data sent by another application or a script can be received.
Name your database in the Finder – that’s the “real” file name. The name you enter in the Database Properties panel will be displayed at the top of views and windows and is up to you. No directory problem will be created.