I have replaced the wifi card by another-one of the same type I had lying around, and it is now recognised. So the card I experienced this problem with is somehow defective.
Sorry about the noise; not sure how I can close this bug report without impsing on you further. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org