Mac OS X, qplugin linker woes...

I am trying to get a program that is functioning (compiles, links, and runs) on Windows to run on the Mac. I am using XCode 2.4 on Mac OS X 10.4.10. I have the program compiling, but I get the following link errors that seem to have to do with qtplugin.h macros. Any ideas about what's going on?

Here is the error output:
Ld /Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/Debug/FlyWorld.app
/Contents/MacOS/FlyWorld normal i386
mkdir /Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/Debug/FlyWorld.app
/Contents/MacOS
cd /Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld
/Developer/usr/bin/g++-4.0 -o /Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/Debug/FlyWorld.app
/Contents/MacOS/FlyWorld -L/Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/Debug -F/Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/Debug -F/Developer/qt/lib -F/Users/tcondon/qt-mac-commercial-src-4.2.2/lib -filelist /Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/FlyWorld.build/Deb
ug/FlyWorld.build/Objects-normal/i386/FlyWorld.LinkFileList -lz.1.2.3 -framework QtSvg -framework QtSql -lQtUiTools_debug -framework QtXml -framework QtAssistant -framework QtGui -framework Carbon -framework QuickTime -framework AppKit -framework QtNetwork -framework QtCore -framework ApplicationServices -arch i386 -Wl,-Y,1455 -headerpad_max_install_names -F/Developer/qt/lib -L/Developer/qt/lib -F/Users/tcondon/qt-mac-commercial-src-4.2.2/lib -L/Users/tcondon/qt-mac-commercial-src-4.2.2/lib -lz -lm -liconv
/Developer/usr/bin/../libexec/gcc/i686-apple-darwin8/4.0.1/ld: multiple definitions of symbol _qt_plugin_instance
/Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/FlyWorld.build/Deb
ug/FlyWorld.build/Objects-normal/i386/FwCustomWidgets.o definition of _qt_plugin_instance in section (__TEXT,__text)
/Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/FlyWorld.build/Deb
ug/FlyWorld.build/Objects-normal/i386/GenericFileHandler.o definition of _qt_plugin_instance in section (__TEXT,__text)
/Developer/usr/bin/../libexec/gcc/i686-apple-darwin8/4.0.1/ld: multiple definitions of symbol _qt_plugin_query_verification_data
/Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/FlyWorld.build/Deb
ug/FlyWorld.build/Objects-normal/i386/FwCustomWidgets.o definition of _qt_plugin_query_verification_data in section (__TEXT,__text)
/Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/FlyWorld.build/Deb
ug/FlyWorld.build/Objects-normal/i386/GenericFileHandler.o definition of _qt_plugin_query_verification_data in section (__TEXT,__text)
/Developer/usr/bin/../libexec/gcc/i686-apple-darwin8/4.0.1/ld: multiple definitions of symbol _qt_plugin_query_verification_data.eh
/Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/FlyWorld.build/Deb
ug/FlyWorld.build/Objects-normal/i386/FwCustomWidgets.o definition of absolute _qt_plugin_query_verification_data.eh (value 0x0)
/Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/FlyWorld.build/Deb
ug/FlyWorld.build/Objects-normal/i386/GenericFileHandler.o definition of absolute _qt_plugin_query_verification_data.eh (value 0x0)
/Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/FlyWorld.build/Deb
ug/FlyWorld.build/Objects-normal/i386/styleplugin_black.o definition of _qt_plugin_instance in section (__TEXT,__text)
/Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/FlyWorld.build/Deb
ug/FlyWorld.build/Objects-normal/i386/styleplugin_black.o definition of _qt_plugin_query_verification_data in section (__TEXT,__text)
/Users/tcondon/Projects/LeapFrog/FlyWorld/FlyWorld/build/FlyWorld.build/Deb
ug/FlyWorld.build/Objects-normal/i386/styleplugin_black.o definition of absolute _qt_plugin_query_verification_data.eh (value 0x0)
collect2: ld returned 1 exit status