logitech z515 wireless speaker not working

[Pierre Frenkiel <pierre.frenkiel@gmail.com>]

hi,
still an other sound problem, this time with a Logitech Z515 wireless speaker.
It worked on my desktop on wheezy, and no more after the upgrade to Jessie.
It works On my wheezy laptop: the Z515 appears in /proc/asound/cards immediatly 
after plugging the usb dongle.
It also works with the Jessie live cd, but with the installed OS, I get in the syslog:

  new full-speed USB device number 3 using uhci_hcd
  New USB device found, idVendor=046d, idProduct=ba10
  New USB device strings: Mfr=1, Product=2, SerialNumber=3
  Product: Logitech Wireless Speaker Z515
  Manufacturer: Logitech
  SerialNumber: 000d4493d340
  snd-usb-audio 7-1:1.0: cannot find the slot for index 2 (range 0-2), error: -16
  cannot create card instance 0
  snd-usb-audio: probe of 7-1:1.0 failed with error -5

  and in /proc/asound/cards, the other cards are seen, but not the X515.

 I become really tired to spend so much time fighting against this OS

 Has anybody an idea  on where to look at?

best regards,
--
Pierre Frenkiel