I've got another problem..
I've installed rogero 999 downgrade (but the ps3 says that it is 3.55 on sys inf. nvm) the i've installed qa toggle from rebug site launched it and waited for 3 bips, then i've tried to make the combo under network setting everything worked fine, then i've tried to install rogero 3.55 3.7 but it failed.. I've quitted and the ps3 restarted fine... but now if i try to make the combo nothing appear..
I've tried to reinstall rogero 999 downgrader...
The file name of rogero downgrader is 3.55 Rogero Downgrader RSOD.pup and its MD5 B67747F529D047D63151786544A58B50
SOLVE

I've used rebug downgrader.