The latest Nikon firmware upgrade "broke" autofocus on three of my Sigma lenses:
180mm f/3.5 Macro
12-24mm f/4.5~5.6 Mk1
150-500mm f/5~6.3
The last two can be upgraded. According to Sigma USA, it's unclear whether the 180mm can be -- but it was upgraded previously to fix the Live View issue so I have some hopes. Either way, it's going to be one big heavy box heading down to New York this weekend.