- rename or delete the current bibliography database over "Tools - Data source"
- open the Bibliography module
-> the module shows an empty (no grid, no form) front-end and the "Choose Data
Source" dialog in the foreground.
This does not tell the user very clearly what happened what is to do etc.

Proposal:

1) If the current Bibliography DB cannot be found when the module is called BUT
other database exist:
-> display a wrning: "The default bilbliography database could not be found. Do
you want to select another one?" / Buttons Ok / Cancel
--> OK: The module opens on an empty database with the "Choose Data Source" in
the foreground.
--> Cancel: does nothing

2) If the current Bibliography DB cannot be found when the module is called AND
no other database can be detected::
-> display a wrning: "There are no registred data source at present" / Button Ok
--> OK: The module opens on an empty database with the "Data source dialog" in
the foreground.

--> Cancel: does nothing