Problem: I have SDK 4.1 installed and try to make a build with Unity iPhone 1.7 (iPhone SDK version set to Unknown). The build doesn’t work on iPhone 3G, because it says it was only made for armv7 architecture and the device is too old to run it.
• Select Targets and Unity iPhone in the left pane of XCode and click the info button (or right-click and choose Get Info)
• Build Tab – Set Architectures from Optimized (armv7) to Standard (armv6 armv7) - Hint: you might want to also set the iOS Deployment Target as low as possible while you’re in there…
• In the menu choose Project > Set Active Architecture > armv6
• Build and run on iPhone 3G!