I used the ruby trick. It didn't work.
I took out the dongle. Did the trick again. It didn't work. I noticed on all the stuff happening that fckpsn always had an ipv4 value different from my ip obtained with ipconfig and put as primary DNS.
Changed that value in the ps3 to match it. Tried to synch my trophies. Synch started after 30 seconds or more
Thanks a lot to whoever coded this stuff. I don't play online but every once in a while I like to synch my hard earned trophies.