Hi Mathias,
This is the tail -n 34 of config.log
configure:5271: checking for Qt
configure:5432: rm -rf SunWS_cache; g++ -o conftest -O2 -fno-exceptions -fno-check-new -W -Wpointer-arith -Wmissing-prototypes -Wwrite-strings -Wno-long-long -Wnon-virtual-dtor -fno-builtin -INO -I/usr/openwin/include   -L/local/kde22/qt-2.3.0/lib -L/usr/openwin/lib conftest.C -lqt -lpng -lz -lm -ljpeg -lXext -lX11 -lSM -lICE -lsocket -lnsl -lresolv 1>&5
conftest.C:2: qglobal.h: No such file or directory
conftest.C:3: qapplication.h: No such file or directory
conftest.C:4: qapp.h: No such file or directory
conftest.C:5: qobjcoll.h: No such file or directory
conftest.C:6: qevent.h: No such file or directory
conftest.C:7: qstring.h: No such file or directory
conftest.C:8: qstyle.h: No such file or directory
conftest.C:9: qiconview.h: No such file or directory
conftest.C:11: #error 1
configure: failed program was:
#include "confdefs.h"
#include <qglobal.h>
#include <qapplication.h>
#include <qapp.h>
#include <qobjcoll.h>
#include <qevent.h>
#include <qstring.h>
#include <qstyle.h>
#include <qiconview.h>
#if ! (QT_VERSION >= 222)
#error 1
#endif

int main() {
    QStringList *t = new QStringList();
    QIconView iv(0);
    iv.setWordWrapIconText(false);
    QString s;
    s.setLatin1("Elvis is alive", 14);
    int magnolia = QEvent::Speech; /* new in 2.2 beta2 */
    return 0;
}

I said "most" but actually, I didn't succeeded in compiling any application using QT since I have upgraded to qt2.3.0

tdebruyn@bru-cse-520% echo $QTDIR
/var/local/user/kde22/qt-2.3.0
tdebruyn@bru-cse-520% echo $KDEDIR
/var/local/user/kde22

Using include and lib flag is probably redundant but I wanted to make sure.

Thanks,
Tom