Were you able to build onto a device?
I was able to get the Simulators to compile by doing this: http://forum.openframeworks.cc/index.php/topic,10343.msg48586.html#msg48586
use iOS 5.1 as the Base SDK
The downside, however, is that I'm getting an error when building to a device.
(null): Linker command failed with exit code 1 (use -v to see invocation)
ld: file is universal (4 slices) but does not contain a(n) armv7s slice: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.1.sdk/usr/lib/crt1.3.1.o for architecture armv7s
clang: error: linker command failed with exit code 1 (use -v to see invocation)
When I attempt removing the architectures as you mentioned, I get this error when the app launches on the device:
Could not launch “Game”
failed to get the task for process 1726
error: failed to launch '/private/var/mobile/Applications/A/Game.app' -- failed to get the task for process 1786