the upgrade option is applying bug fixes but it can also apply support for other hardware. right now this function is not adding support for hardware.
regarding your issue with Zalman box, there is something which should make things to work. install pluto-irtrans-wrapper (which is a implementation of irtrans
package). i never played with this but it should work. also read this page http://www.mythtv.org/wiki/index.php/Zalman_HD160