Marc,
If an Ingest were to be aborted abruptly because a card was removed in some uncontrolled fashion, you should re-mount the card. Then look at the destination folder and find the highest sequence number assigned. Add one to the sequence number and set the sequence number to that value in the Ingest dialog (click the "Set sequence..." button). Continue the Ingest. Files should not be duplicated. We checked the code and Ingest writes the ID data file on the card very early in the Ingest process, and the local "files ingested" data file is updated each time a file is successfully copied. All successfully copied files should be skipped when doing subsequent incremental Ingests.
How are your cards getting disconnected?
-Kirk