The BDROM package is for resetting the Mounted game. It removes it from the PS3 XMB and also restores your usb external drive to usable state in PS3 XMB. If you have an External with stuff. It's a good Tool to have. I recommend it. :)
R3 is refresh aint it?
Edit: OK, I see Start + L3 is rescan. I've noticed sometimes(If a drive is plugged in after Multi-Man is loaded. But not very often.) that even after rescan it doesn't reload. Hit the R3 after and see if that helps.

