linker problems while building GWorkspace on Mac OS X

[LHelldorf]

All the files now compile fine using Project Builder. I also changed the 
build process, now using an Aggregate Target which holds several other 
Targets (of type Application and Bundle). Anyway I keep getting errors 
from the linker like this:

/usr/bin/ld: warning prebinding disabled because of undefined symbols
/usr/bin/ld: Undefined symbols:
.objc_class_name_NSAutoreleasePool
.objc_class_name_NSConnection
.objc_class_name_NSFileManager
.objc_class_name_NSMutableArray
.objc_class_name_NSNotificationCenter
.objc_class_name_NSObject
.objc_class_name_NSRunLoop
.objc_class_name_NSString
.objc_class_name_Protocol
_NSConnectionDidDieNotification
_NSLog
__NSConstantStringClassReference
_objc_msgSend
_objc_msgSendSuper

    /usr/bin/cc  -o 
"/Volumes/Data/GWorkspace/build/backgrounder.app/Contents/MacOS/backgrounder" 
 "-L/Volumes/Data/GWorkspace/build" 
"-F/Volumes/Data/GWorkspace/build/ProjectHeaders" 
"-F/Volumes/Data/GWorkspace/build"  -filelist 
"/Volumes/Data/GWorkspace/build/intermediates/backgrounder.build/Objects/LinkFileList"
 
 "-arch" "ppc" "-prebind" 

...failed StandaloneExecutable.LinkUsingFileList 
/Volumes/Data/GWorkspace/build/backgrounder.app/Contents/MacOS/backgrounder 
...

Does anybody know what to do here?

Thanks in advance, Lars