: I'm on 4.20 DEX mate, no peek n poke (I don't launch MM to play games anymore). 3.55 DEX should work too, once the PARAM.SFO is right.
I redirect app_home to a directory on my PC using Target Manager, I select the "BLES00000" folder with PS3_GAME inside and Fself every .bin/.self/sprx that needs it, then most of them work.
If that doesn't work, editing the .elf of the EBOOT to use app_home instead of dev_bdvd has a much better success rate (SSX being one example, RD: GRID and a few other recent releases work that way too). I just do it to save buying loads of HDD's for my PS3's n 360's or moving USB drives around etc.
TL;DR - There's no disk inserted.