For those who are interested, I finally switch USB Tuner. I took the one distributed by SKY in Italy with an aver media in it.
Everything is working great on my ET9500 with OpenPli 3.
I took this one because I tried 4 different model (Wintv Nova-t, WinTV ministick and Sundtek)
The SKY usb key was the one that found all the channels available. Everything is working well with HD channels.
Hope this will help !