Just backup and edit the file
and add the magic words in red as below
Please remember to restart your Xcode after the amendment above.
I have tested it to build app on jailbreaked iPhone firmware 2.1 & 2.2
For MobileInstallation patch, please use my package as posted here
If you have "security policy error" after Build & Go. Do these steps
(1) Install a new free app from App Store in iPhone (not sync from iTunes)
(2) Launch that newly purchased free app and then close it.
(3) Reboot your iPhone (that is power off and on again)
(4) Launch the app again that you have Build & Go in Xcode to iPhone.
Please also refer to the latest article for SDK2.2.1