This question no longer applies to current versions of Ubuntu.
See Problem with .deb packages on Ubuntu 16.04 for a similar problem affecting 16.04.
I'm running Ubuntu 11.10 and have some problems with Ubuntu software center and the installation of debian packages.
If I download for instance the debian from https://www.virtualbox.org/wiki/Linux_Downloads and try to install with Ubuntu software center I got the window opening but I can see only the GTK Spinner.
The problem exists also with the package of my applications http://www.giuspen.com/cherrytree/ and http://www.giuspen.com/x-tile/ which I create with dpkg-buildpackage,
The same packages are opened and installed properly with gdebi.