I am not sure but maybe after an upgrade to net-wireless/irda-utils-0.9.18-r3 I can no longer blacklist smsc-ircc2. I ran update-modules, checked /etc/modprobe.conf and "blacklist smsc-ircc2" is there. I noticed that net-wireless/irda-utils-0.9.18-r3 has a udev rules file that I do not remember being there before so I thought the problem might be there. I am also running sys-fs/udev-119 in case something has changed there. Reproducible: Always
Are you still able to reproduce on full updated system?