Rick
Firmware upgrades can fix a number of "oversights" with the original production of a receiver, but can also "upgrade" existing decoding formats.
With my Marantz SR8200, I have an option of upgrading the receiver to where the time that it takes to automatically detect the surround format is much much faster. With the same $200 upgrade, I can upgrade the Circle Surround 5.1 format to CSII 6.1, enhance the dolby digital and dts bit rates to "32 bit" by passing the signal twice throug the DSP chips, and upgrade the DTS to DTS 96/24 for compatible titles.
Since this particular upgrade entails so many enhancements, it can only be done by an authorized facility in Illinois. I'm not sure if you would be able to have any "user upgrades" available to you with an HK.
Hope that helps!
Regards
JC
