Qt 4.1.1, no use of uic with qmake?

Hi. With a very simple project in Qt 4.1.1, I get no call to uic when I use qmake.

qmake -project "CONFIG -= debug_and_release debug_and_release_target"
qmake
make -f Makefile

gives no call to uic to compile the userinterface. Strange!

The .pro file contains:

CONFIG -= debug_and_release debug_and_release_target
TEMPLATE = app
TARGET +=
DEPENDPATH += .
INCLUDEPATH += .

# Input
HEADERS += mainwindow.h Project1_private.h
FORMS += mainwindow.ui
SOURCES += main.cpp mainwindow.cpp QT.mak.cpp

Strange.
Any ideas?

Do you include ui_mainwindow.h somewhere?

No but mainwindow_ui.h which doesn't work.
ui_mainwindow.h works much better.