That would be because it wont run from USB at all.. Was never intended to.. So there is nothing wrong with Rebug.. It is doing exactly what it should do when run from USB.. It will lock up RSOD.. Rebug is made as a replacement FW.
Also how can they can't block it (Rebug) specificaly if it (PSN trick) isn't there.. That is why I didn't include the PSN access.. It isn't ready yet..