more about osso-system-version here: http://lists.maemo.org/pipermail//ma...ry/013750.html
(see the original e-mail by Markus Vollmer at the bottom of the thread)

Bottom line: if you want to tinker with essential system packages you probably have to remove osso-system-version (although I haven't). That might create issues in later system upgrades, as R-R says.