I think you're running into the same issue I was. Grab the latest build of the package:
http://www.opensolaris.org/os/community/laptop/downloads/ath-0.6-pkg.tar.gz Remove the old driver and install that. I believe it should be pkgrm SUNWatheros then pkgadd -d SUNWatheros (in the directory you extract that to). This message posted from opensolaris.org
