32-bit libraries on Mac OS X 10.6 missing from install?

[tkrajacic]

Forgive me if this is a stupid question.

Why is QtCore.framework 64 bit only on Mac OS X?
@[lib/QtCore.framework]% file QtCore
QtCore: Mach-O 64-bit dynamically linked shared library x86_64@

I tried building a simple 32bit C++ library and wanted to use some Qt libraries and I always get the error:
@Undefined symbols for architecture i386:
"QString::fromAscii_helper(char const*, int)", referenced from:
QString::QString(char const*)in cciLB4my.o
"QString::free(QString::Data*)", referenced from:
QString::~QString()in cciLB4my.o
"QLibrary::QLibrary(QString const&, QObject*)", referenced from:
_main in cciLB4my.o
"QLibrary::load()", referenced from:
_main in cciLB4my.o
"QLibrary::~QLibrary()", referenced from:
_main in cciLB4my.o
ld: symbol(s) not found for architecture i386
collect2: ld returned 1 exit status@

Now I came across another post in this forum which mentions that I have to build the 32-bit Libraries on Mac OS X myself.
Is this true?

Can I just build the libs, because I don't want yet another installation of Qt. (I installed 4.7.3 from the website using the Online-installer)
Can I just put them beside my existing libs? (At the moment my Qt installation is under ~/Dev/Qt/... can I just put them in a parallel directory to the libs in the current installation e.g. "lib32") Or better said how would it be most practical since I am using Qt Creator and I then would like to build 32-bit only.

Sorry for asking such basic questions but I never worked with Qt Creator or even Qt before.

If someone could share a little insight I would be very happy.

Thomas Krajacic