The Rogero 4.25 -3.55 Downgrader hybrid pup will show 4.21 in System Settings. And it will say 4.40 as well when trying to update from Recovery. Make sure Original Logic board is intact and Blu ray is attached to PS3. Try running Toggle_qa again. This means to install it, then run it from XMB
The screen will go Black and you will see HDD Led activity then if all went fine you will hear one Beep and the PS3 will Restart back to XMB. Then try installing Rogero 3.7 in Recovery, just press SELECT + START for about 5 seconds
Once that is successful install 3.55 OFW in XMB and then once again in Recovery and you will be dehashed.