earlier i had this issue of freezing at logo screen. ysday after reading i did the following and GT5 WORKS jus fine!!!! awsome game!
1. I downloaded GT5 BCES00569 and transferred the game into ma ps3 ("hdd0/game/xxxx/GAMEZ/BLES00569" xxxx refers to ur backup manager)
2. Edited jus the param.sfo to 3.41 (EBOOT ws already patched i guess)
3. downloaded FIX_PERMISSIONS_Waninkoko_Kmeaw_CFW_3.55.pkg and installed in my PS3 (3.41 with 3.55 spoof) you can get the 3.41 with 3.55 spoof
4. Before every start of the game click on "FIX permission blah blah" at the xmb and open MULTIMANAGER to load the game!
5. a retail disc on d console and GT5 is ready to get started! awsomeness...
I'm now a level 7 A spec driver! All the best guys and assuming it really helped certain people!
oh yes one more thing when loading game from Multi manager, just click R1 (patch mode) and load!