[win32][platform win32-g++-4.6] qtdemo fails to find installed demos and examples

For example, I build Qt-4.8.1 in C:\qt\qtbuild with following commands:
configure.exe -debug-and-release -opensource -platform win32-g++-4.6 -prefix C:\Qt\4.8.1
mingw32-make
and install with
mingw32-make install

then qtdemo.exe fails to find installed examples. In build dir examples are in subdirectories "debug" and "release", but installed only one version and without subdirectory. For, example, in build dir there is demos\boxes\debug\boxes.exe and demos\boxes\release\boxes.exe, but in install dir there is only demos\boxes\boxes.exe.

Qt should install both versions in subdirectories to match build dir or patch qtdemo.exe sources. Patch is attached (for file demos\qtdemo\menumanager.cpp). First way (patch install process) is better IMO.