>The form uses tableupdate(.t.,.t.) to save the data. I don't know where to check the buffering? The buffer mode is optimistic. Fox pro doesn't respond as if an error occurs, it just doesn't load the form properly with the new data. SQL saves the error in the log however.

You can use CURSORGETPROP("BUFFERING") to determine what the buffering is. If you are using row buffering (rather than table buffering), VFP will implicitly issue a TABLEUPDATE anytime the record pointer is moved. So if you are doing a search on the remote view, maybe a TABLEUPDATE is occuring that you are not aware of, and this is triggering the error.