I'm not too sure what you are asking or saying. Are you saying when you go to install pkg files on the xmb you get nothing but a black screen?? I would say to install XMB_Manager_Plus_v0.10 which you can get here: http://www.mediafire.com/?c1yzarmcc94lxj2
but you wont be able to install it can you install a pkg file straight from multimans file manager just try to click on any pkg file and it should ask if you want to install the pkg.
Let me know if I was correct and if that is what you are saying is wrong with your ps3 you click install pkg files and you get a black screen... for info the usb flash drive you have pkg files on needs to be formatted to fat32 or it will not read any pkg files and will stay on the black screen are you able to press circle and it goes back to xmb if so that may be the case.