virtualbox.org

Any help here?
Running Ubuntu 8.04, with newest virtualbox in repo - same as on VBox site.
I get:
VirtualBox: supR3HardenedMainGetTrustedMain: dlopen("/usr/lib/virtualbox/VirtualBox.so",) failed: /usr/lib/libQtGui.so.4: undefined symbol: _ZN23QCoreApplicationPrivate19checkReceiverThreadE P7QObject

Searches seem to point to a bug in qt4. Any ideas?
Thanks

SOLVED:
Following the spirit and sense indicated by the link from the previous post, I found I had both libqtcore4 and libqt4-core installed. I removed the first and reinstalled the second, and lo, virtualbox launches. Thanks stefan and those you linked to.