This is the code:

        // TODO: the config file isn't being written to disk. Why oh why??
        // I don't know. But this obviously leads to crashes if other konqueror
        // instance tries to read this closed window item from a non existant
        // config file.
        kDebug() << "WRITE TO DISK: " << closedWindowItem->configGroup().config()->name();
        closedWindowItem->configGroup().sync();

This is the output:

konqueror(22794) KonqClosedItemsConfig::KonqClosedItemsConfig:
konqueror(22794) KonqClosedWindowItem::KonqClosedWindowItem: "Closed_Window138991264"
konqueror(22794) KonqUndoManagerCommunicator::readConfig: WRITE TO DISK:  "closeditems/closeditems_22794"
konqueror(22794) KonqClosedWindowItem::KonqClosedWindowItem: "Closed_Window144776704"
konqueror(22794) KonqUndoManagerCommunicator::readConfig: WRITE TO DISK:  "closeditems/closeditems_22794"
konqueror(22794) KonqClosedWindowItem::KonqClosedWindowItem: "Closed_Window144785024"
konqueror(22794) KonqUndoManagerCommunicator::readConfig: WRITE TO DISK:  "closeditems/closeditems_22794"
konqueror(22794) KonqClosedWindowItem::KonqClosedWindowItem: "Closed_Window144788688"
konqueror(22794) KonqUndoManagerCommunicator::readConfig: WRITE TO DISK:  "closeditems/closeditems_22794"


But the file is not being written to disk!

edulix@edulix-laptop:~/proyectos/kde4/kdesvn/kdebase/apps/konqueror$ ls /home/edulix/.kde4/share/apps/konqueror/closeditems
edulix@edulix-laptop:~/proyectos/kde4/kdesvn/kdebase/apps/konqueror$