compilation Error

[vetic]

Hello, I use phonegap 2.1.0 and in the moment of I compill with xcode 4.5 I have this error

Undefined symbols for architecture i386:
"OBJC_CLASS$_CDVPlugin", referenced from:
OBJC_CLASS$_VTCShare in VTCShare.o
"OBJC_CLASS$_CDVPluginResult", referenced from:
objc-class-ref in VTCShare.o
"OBJC_CLASS$_CDVURLProtocol", referenced from:
objc-class-ref in AppDelegate.o
"OBJC_CLASS$_CDVViewController", referenced from:
OBJC_CLASS$_MainViewController in MainViewController.o
"OBJC_METACLASS$_CDVPlugin", referenced from:
OBJC_METACLASS$_VTCShare in VTCShare.o
"OBJC_METACLASS$_CDVViewController", referenced from:
OBJC_METACLASS$_MainViewController in MainViewController.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Do you understand how to correct this?