I have a similar problem. Followed the instructions on (this site) tut: installing-on-asus-routers-rt-n16-etc-in-linux three times. Left it flashing for 5 minutes, 30 minutes and an hour. I cleared nvram twice by holding down the red button for 30+ seconds during power up. The power light came on solid for about 10 seconds and then went to slow flash. I cannot ping the router. This is a brand new unit, is it possible ASUS made an incompatible hardware mod?
Sorry I can't publish links so what almost looks like a link needs fixing.
I loaded the trx file in tomato-K26USB-1.28.9054MIPSR2-beta-Ext.rar. It did apparently download cause the link light flashed for a few seconds. The lan light stayed on and the power light went out.