Thanks for the links!

If I understand I can go to the QtDir and type: make confclean, then run the ./configure script with the wright options for sql pluggins: -pluggin-sql-<driver>

or build the QPSQL Plugin on Unix and Mac OS X manually
(for psql)

cd $QTDIR/src/plugins/sqldrivers/psql
qmake -o Makefile "INCLUDEPATH+=/usr/include/pgsql" "LIBS+=-L/usr/lib -lpq" psql.pro
make

My Qt-installation lack the src-dir under QTDIR and I can't find out how to download just the source. the link: ftp://ftp.trolltech.com/qt/source refers only to full Qt-installations, or am I wrong?

Is it a configure option to specify that the src-dir should be downloaded too ? I can't see that from the ./configure -options