Samsung SW-248F FW 604 Not recognized by Nero 6

HI there
I just flashed my Samsung SW-248F from FW 602 to 604 with the FW supplied here.
And Nero cannot use the burner anymore. Symptom: it does recognize the drive (in the list of available ones) but it cannot get it ‘ready’ and the list of available speeds remains empty. So the Burn button is greyed out.
What should I do ? Should I reverse to previous FW? where can I find it ?
Thanks

Try deleting the drive from Device Manager, then restart the computer.