title: My app is running on the simulator but not on the device
body: <p>I have a problem with that error :</p>
  
  <pre><code>Undefined symbols for architecture i386:
  </code></pre>
  
  <p>When I build and go, it run successfully on the simulator but not on the device, I try a simple new project, I try to run it on the device, it was ok, but this project didn't run because of that error, the full stack error is this :</p>
  
  <pre><code>Ld "/Users/imac/Library/Developer/Xcode/DerivedData/TopStation-cjwcuxabgkltqvdslykmwkeqvsee/Build/Products/Debug-iphonesimulator/RM Unit Tests.app/RM Unit Tests" normal i386
      cd /Users/imac/Desktop/route-me-route-me-b07b654/MapView
      setenv MACOSX_DEPLOYMENT_TARGET 10.6
      setenv PATH "/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
      /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/gcc-4.2 -arch i386 -isysroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.3.sdk -L/Users/imac/Library/Developer/Xcode/DerivedData/TopStation-cjwcuxabgkltqvdslykmwkeqvsee/Build/Products/Debug-iphonesimulator -F/Users/imac/Library/Developer/Xcode/DerivedData/TopStation-cjwcuxabgkltqvdslykmwkeqvsee/Build/Products/Debug-iphonesimulator -filelist "/Users/imac/Library/Developer/Xcode/DerivedData/TopStation-cjwcuxabgkltqvdslykmwkeqvsee/Build/Intermediates/MapView.build/Debug-iphonesimulator/Unit Tests.build/Objects-normal/i386/RM Unit Tests.LinkFileList" -mmacosx-version-min=10.6 -framework Foundation -framework UIKit -Xlinker -objc_abi_version -Xlinker 2 /Users/imac/Library/Developer/Xcode/DerivedData/TopStation-cjwcuxabgkltqvdslykmwkeqvsee/Build/Products/Debug-iphonesimulator/libProj4.a -framework CoreFoundation -framework CoreGraphics -framework CoreLocation -framework Foundation -lsqlite3 -framework QuartzCore -framework UIKit -o "/Users/imac/Library/Developer/Xcode/DerivedData/TopStation-cjwcuxabgkltqvdslykmwkeqvsee/Build/Products/Debug-iphonesimulator/RM Unit Tests.app/RM Unit Tests"
  
  Undefined symbols for architecture i386:
    "_OBJC_CLASS_$_RMDBTileImage", referenced from:
        objc-class-ref in RMTileImage.o
  ld: symbol(s) not found for architecture i386
  collect2: ld returned 1 exit status
  </code></pre>
  
  <p>I changed the build mode, so I have choosed the device(in my case i use an iPod 4.3.5), now I have an other error :</p>
  
  <pre><code>'FavoriteCities.app' was built for 'i386', but the device 'iPod (Imac)' requires 'armv7' or compatible architecture.
  </code></pre>
  
  <p>FavoriteCities is my application name, please help me to figure out what could be the problem causing all that.</p>