For the WRT54G we recommend DD-WRT build 22118, from here:
http://download1.dd-wrt.com/dd-wrtv2/downloads/betas/2013/07-24-2013-r22118/broadcom/dd-wrt.v24_std_generic.bin

I tried to upgrade to this firmware from 14998 build of dd-wrt and now my router is bricked…