iOS 4应用程序在iOS 3.1.3启动时崩溃:符号未找到:__nscalcultestackblock

I'm running Xcode 3.2.3 with the iOS 4.0 SDK. I built my app with Base SDK = iphoneos4.0, Active SDK = iphoneos4.0, Deployment Target = 3.1.3, and Architecture = standard (arm6 arm7). Compiler = GCC 4.2. As I understand it, this is the correct way to I'm running Xcode 3.2.3 with the iOS 4.0 SDK. I