who's the good way to dock an app?

[Chema]

Hi all:
I try to dock an app and always crash.
I see the error is similar error that's happends with kautorun:
0x40c42019 in __wait4 () from /lib/libc.so.6
#0  0x40c42019 in __wait4 () from /lib/libc.so.6
#1  0x40c9f718 in __DTOR_END__ () from /lib/libc.so.6
#2  0x402ad8d0 in KCrash::defaultCrashHandler ()
   from /opt/kde/lib/libkdecore.so.3
#3  0x40bdf9e8 in __restore ()
    at ../sysdeps/unix/sysv/linux/i386/sigaction.c:127
#4  0x40780627 in read_png_image () from /usr/lib/qt/lib/libqt.so.2
#5  0x40723789 in QImageIO::read () from /usr/lib/qt/lib/libqt.so.2
#6  0x407216a1 in QImage::load () from /usr/lib/qt/lib/libqt.so.2
#7  0x4071a9d2 in QImage::QImage () from /usr/lib/qt/lib/libqt.so.2
#8  0x4028acd5 in KIconLoader::loadIcon () from /opt/kde/lib/libkdecore.so.3
#9  0x4028db11 in SmallIcon () from /opt/kde/lib/libkdecore.so.3
#10 0x400fda75 in KSystemTray::showEvent () from /opt/kde/lib/libkdeui.so.3
#11 0x407d466e in QWidget::event () from /usr/lib/qt/lib/libqt.so.2
#12 0x406f1c99 in QApplication::notify () from /usr/lib/qt/lib/libqt.so.2
#13 0x4025c2b6 in KApplication::notify () from /opt/kde/lib/libkdecore.so.3
#14 0x407d2f45 in QWidget::show () from /usr/lib/qt/lib/libqt.so.2
#15 0x804ea7b in main ()
#16 0x40bd9a8e in __libc_start_main () at ../sysdeps/generic/libc-start.c:93
I try with KSystemTray & with KDockWindow but it crash...
Regards
Chema