I installed the 575 firmware version to test it out and it seems to hash less then the turbo firmware. Is there something you changed besides frequency?  My miner on turbo mode 550mhz I hashed an avg of 49 to 51.  And now my avg. Is 47 on 575mhz.  So not sure why now it is getting less with your firmware. Any help will be appreciated. Sucks to now make less