Jakob,
1. You need to check on the export side to see if the tables were exported (check export package log files)
.
2. You need to check your import logs (assuming the tables were exported).
3. Did you run the SMIGR_CREATE_DDL report on your source system before starting the export ?
If I may ask, have you ever done a OS/DB before (will help me in how I formulate my replies) ?
Amerjit