Hello and thank you for your help.
I have never had any problems until now. It happened that the driver jumped following a windows update, I just had to reinstall it and the problem was solved.
My configuration:
Win 7 pro 64
Saffire USB 6 card
driver 1.1 supplied with the card (I tested the latest ones, same thing)
Java supplied with the REW installer
My card is recognised by my PC and works perfectly in other applications
I've just tried it in Java and it works, it's in ASIO that it doesn't work any more, I've always configured in ASIO until now