Hi 3351, you just helped me one month ago suggesting to update firmware, but I'm afraid this time my problem is really bad...... yes I tried to uninstall/reboot/reinstall drivers pack but nothing changed...... I didn't try reset to factory (good idea!), but I don't understand where to search (Windows or hardware?). OK for filtering, but I regularly check MOTU web site where you can see immediately if they replied (nothing for the moment......). Thank you for your help.