I just noticed this on the bitmain site:
https://bitmaintech.com/files/download/antMiner_S320140811.binThe notes just say "added advanced frequency" which means there is an extra tab for overclocking in the miner configuration page...just flashed now thought I would give a heads up to you all

Edit: in order for the frequency and firmware to work and not come up blank, I used the "save settings" box when flashing the firmware, then after the flash is complete and the miner has rebooted, go to the miner config/advanced tab and hit apply on the frequency you want (it defaults to 237.5 and no idea why 100 is in there), then hit apply on the main miner config page to be safe, then reboot the miner...works for me!