I have found that the tutorials on this do not figure in the differences in paths in certain games. I suspect that these same differences are what caused certain games to black screen when originally launched from backup managers.
Try to search for more instances of dev_bdvd in the hex and see if the are part of a path. If so change all the appropriate ones to dev_hdd0.
Also pay attention to what comes after dev_bdvd, genarally it goes dev_bdvd/PS3_GAME but this is not always the case. Whatever does come after it, in all instances change it to something that is the same size. I always use the first 3 letters of the game name, then the _ then the next 4 letters of the game name. This is then the folder you create in dev_hdd0 to ftp the USRDIR into.
I hope this is clear and not confusing and I hope it helps you.