any help? sdk app - worked, now not working

[nownot]

this one seems unsolvable. i have a app that i wrote in the sdk, i did the codesign -s "name" -f foo.app and it worked on my iphone as well as my friends. i re-pwned mine to change the boot logo, now it wont work. but like i said it worked on the previous installation. i also tried doing ldid -S foo.app/foo this doesnt work for me either. i have tried different ipsw and everything i can think of. now i believe it is a setting in the phone somewhere, can anybody think of any reason why im running into this problem? thanks for any help.