First af all really thanks for the answers and patience.
I know how to downgrade,and believe me i read the entire posts .
I just tried again with fw 7.20 with no succes ,im trying now with 7.0 and then i will try with 6.60 (the one you recommend).
I did the whole ting (updater with xxx.rgn then clearnonvol,extract reg _140,modify extracted reg_140 and xrgn to device),the curious thing was that when i went to modify my new extracted reg_140 with the Mod_3xxx.exe i notice that they already have enable things ,so i supposed that when you change the full FW its include a clear 140 region.
Im really sorry about i lift your preasure next post i will tell good news !!!
ps: either because I could do it or because it became a brick.