Ok, grab this: http://people.freebsd.org/~adrian/ath/20130403-ath-rx-unmap-first-2.diff then patch this: cd /path/to/blah/sys/dev/ath/ svn revert *[ch] patch -p0 < patch I'm running this on an AR9580 with the above patch. No issues now. The problem? PREREAD doesn't do what I thought it does. Adrian