At least for me, this bug is fixed with version 2.6.15-8 (backports.org: 2.6.15-7bpo1). It is also mentioned in the changelog:
linux-2.6 (2.6.15-8) unstable; urgency=high [ maximilian attems ] * Add stable Release 2.6.15.5: [...] - Address autoconfiguration does not work after device down/up cycle Cheers Harry -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]