QSettings doesn't handle qulonglong values properly

If you set a value to a QSettings and then retrieve it, you will get some unexpected results on Windows 7 (be it 32-bit or 64-bit) and OS X 10.8.2 while it works as expected on Ubuntu 12.04 (both 32-bit and 64-bit).

Attached is some code that illustrates the issue at hand.

Output on Windows 7:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test(pValue);
---> pValue: 4294967295

QSettings settings;
settings.setValue("Test", pValue);
qulonglong retrievedValue = settings.value("Test").toULongLong();
---> retrievedValue [Expected]: 4294967295
---> retrievedValue [Actual]: 0

---------------------------------------

test(pValue);
---> pValue: 4294967296

QSettings settings;
settings.setValue("Test", pValue);
qulonglong retrievedValue = settings.value("Test").toULongLong();
---> retrievedValue [Expected]: 4294967296
---> retrievedValue [Actual]: 0

---------------------------------------

test(pValue);
---> pValue: 4294967297

QSettings settings;
settings.setValue("Test", pValue);
qulonglong retrievedValue = settings.value("Test").toULongLong();
---> retrievedValue [Expected]: 4294967297
---> retrievedValue [Actual]: 0
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

and on OS X 10.8.2:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
test(pValue);
---> pValue: 4294967295

QSettings settings;
settings.setValue("Test", pValue);
qulonglong retrievedValue = settings.value("Test").toULongLong();
---> retrievedValue [Expected]: 4294967295
---> retrievedValue [Actual]: 18446744073709551615

---------------------------------------

test(pValue);
---> pValue: 4294967296

QSettings settings;
settings.setValue("Test", pValue);
qulonglong retrievedValue = settings.value("Test").toULongLong();
---> retrievedValue [Expected]: 4294967296
---> retrievedValue [Actual]: 0

---------------------------------------

test(pValue);
---> pValue: 4294967297

QSettings settings;
settings.setValue("Test", pValue);
qulonglong retrievedValue = settings.value("Test").toULongLong();
---> retrievedValue [Expected]: 4294967297
---> retrievedValue [Actual]: 1
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~