It took me a bit of fiddeling but I finaly got to par with the alsa_usb module
and how to use it. I didn't find any documentation or clues how to use it,
just issues with it. I have written a small patch to the LIRC FAQ in the hope
that it will help further searches.
The attached patch also includes a small addition to the issue about having to
press the remote's button twice, since I had this problem with a SB Extigy.