You need the latest multiman and for some people who still couldn't get past black screen have used iris manager. So external, BD-Mirror, disc in PS3 , the fix for 3.55 and you may have to set permissions in multiman.
If you still have issues, recopy the game to your external hdd. Could very well be copying issue as well.
This is why we ask questions, in order to better help you. Or as said above, try a few things.
Installing the latest multiman won't wreck your other games either.
Download 4.20 full: http://www.ps3news.com/forums/ps3-ha...tml#post451044
Then download and install 4.30 Base CEX, 4.40 Base Cex, and finally 4.50 Base Cex: http://www.ps3news.com/forums/misc.p...ments&t=118726