I DID IT!!!!!!
Thank you all!!! the epiphany was this last message from Lucky1!
The problem is not in the firmware, is in linux. I can't figure why, but I downgraded the firmware on the router to release 1.04 via web interface, and USING FIREFOX ON WINDOWS I was able to flawlessy upgrade the firmware to the current standard openwrt version via the recovery form.
Now it works with luCI and all the stuff.
I think that we have to write about this strange behavior on the dir-2660 page of the openwrt wiki