[NSCoderNightDC] Weird Xcode thing?

Hey,

Trying to compile and I'm getting Apple Mach-O Linker Errors:

Undefined symbols for architecture armv7s:

  "_AudioServicesCreateSystemSoundID", referenced from:

      -[ClassicThemeViewController buttonClick:] in ClassicThemeViewController.o

  "_AudioServicesPlaySystemSound", referenced from:

      -[ClassicThemeViewController buttonClick:] in ClassicThemeViewController.o

  "_AudioServicesDisposeSystemSoundID", referenced from:

      -[ClassicThemeViewController buttonClick:] in ClassicThemeViewController.o

ld: symbol(s) not found for architecture armv7s

clang: error: linker command failed with exit code 1 (use -v to see invocation)

But, I have these imported:

#import <AVFoundation/AVFoundation.h>

#import <AudioToolbox/AudioToolbox.h>

and the AVFoundation.framework in my list of Libraries to Link with Binary…

Is this one of those flakey Xcode things where you need to trash your project and start over?  Or am I missing something?

-Jon