Do you have 3.41?
Did you put the 2 files in the /lib/firmware folder?
Did you put the "insmod /root/psfreedom.ko" and the "exit 1" at the beggining of the osso-usb-mass-storage-enable.sh file?
...
I have to say that I have the same problem, but it seems to be a "non-3.41" firmware issue. I tried to hack my ps3 yesterday with the same results, blank screen everytime.