Many DDwrt builds are faulty.
Be sure to use build 22118 and reset the configuration during flashing. Build 22118 can be found here: http://dd-wrt.com/site/support/other-downloads?path=others%2Feko%2FBrainSlayer-V24-preSP2%2F2013%2F07-24-2013-r22118%2F
