Import....with error Capability not supported


First some details....
Within my applicatin a created 2 tables/datasources called TBLwww and
The appplication uses TBLwww (www.db). In the application it's possible
to import a
database. The user can select a database (always called www.db) from any
of his diskette/harddisk/netwerkdrive. The idea why this databases also
called www.db is
that when I use it at home, put the www.db on disk, and on my work i
this database. When the user select a database (used OpenDialog) the
path will be assign
to a var. (sSource) which will be assign to TBLimport.Databasename.
Now BatchMove can run because BatchMove.Destination= TBLwww and
BatchMove.Source = TBLimport.

The problem is that I need to prevent the user select the active www.db
which is in use by the application. To prevent this I also created a
var. (sDestination)
and assign the path of the active database to it. Compare both
var.....and if they are the same
a message will be ! BUT....for some reason there is a
step before...
which I can't find. When I select the active database, by using the
OpenDialog component,
and click on the 'Open' button the message "Capability not supported'
will be displayed
on my screen....! After that it's possible to close this screen and exit
the application.

a. On which point does this error appears and how can I prevent it
b. Some ideas for a good/nice import example

Greetings Peter