Cannot remove IBM atdd driver ...

[Anovo]

Hi,
We’ve now finished our test with IBM LTO drives; the atdd driver has been uninstalled (swremove) to fail back to the previous configuration (stape driver with HP drives).
Unfortunately, each time we rescan the tapes, (ioscan –fnC tape) the tape device is listed as “unclamained” with the atdd driver…
The kcmodule command reports that the atdd module is not loaded. However there is still one entry for the atdd device driver (lsdev), with the Class set to unknown.
The stape module is loaded (static – explicit) and the server has been rebooted several time (without tape devices connected, then with one connected, …) but the result is still the same.
Any idea ??? TIA
Stephane.