i succeeded to restore tomato firmware to build 52.
after i reseted the router i had access to 192.168.1.1 up to a some kin of mini asus web server where I could uplaod the original asus firmware, then the dd-wrt special trx file and then the tomato build 52 file…. and now i have a fully functionable ASUS RT-N10 with tomato firmware on it and it works great.
after you follow the steps specified by others for entering recovery mode check to see if you have the recovery web server available.
And also use a ping command like "ping -t 192.168.1.1" continuously to see when the router is online (sometimes it stops responding to pings when in recovery mode and tftp will not work and web server also).
my only issue is that the web interface is very ugly but this doesn't matter as long is it works.