Apparently they are tougher. Need to configure it as a wireless repeater while enabling wpa2. I´ve never understood how linksys can sell repeaters (or before when they sold the high gain antennae) at prices that are very similar to the WRT54G, when they could have just enabled the option on them.
well, dig in! http://www.dd-wrt.com/wiki/index.php/Main_Page
** update :D **
I am happy to report that instructions were very well done. I followed this to the letter and now I am off to my parent´s house to install the last part, a wireless repeater bridge :D