Thank  you Jason. I have a main datamodule with the connection and some queries, nothing else; I also have several datamodules which perform different specialized functions, all connected to the main datamodule's connection: most of these datamodules use ClientDataSets. At first I had all the components working without explicit transactions; that didn't work, so I used an explicit transaction on the misbehaving table. So far I can't read the last inserted rows in that particular table. Anything you would like to see?