Quando crio meu aplicativo com o Xcode 4, ele sempre mostra esta mensagem de erro:

CopyPNGFile /Users/michaelchen/Library/Developer/Xcode/DerivedData/iMusicBox-boeawugacmhacbdtyymnprzfobyq/ArchiveIntermediates/iMusicBox/InstallationBuildProductsLocation/Applications/iMusicBox.app/list_cell.png Images/list_cell.png
    cd /Volumes/WORK/Works/iMusicBox
    setenv PATH "/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
    "/Developer/Platforms/iPhoneOS.platform/Developer/Library/Xcode/PrivatePlugIns/iPhoneOS Build System Support.xcplugin/Contents/Resources/copypng" -compress "" /Volumes/WORK/Works/iMusicBox/Images/list_cell.png /Users/michaelchen/Library/Developer/Xcode/DerivedData/iMusicBox-boeawugacmhacbdtyymnprzfobyq/ArchiveIntermediates/iMusicBox/InstallationBuildProductsLocation/Applications/iMusicBox.app/list_cell.png

Enquanto verifica os alfas em /Volumes/WORK/Works/iMusicBox/Images/list_cell.png pngcrush capturou o erro libpng: dados de imagem insuficientes

mas tudo bem com o Xcode 3.2 - por qu