Upgrading a home theater receiver (not replacing)

With the increased abilities of home theater receivers (AVR) comes increased complexity and the possibility of bugs.  Most current mid-range to high end receivers have HDMI 1.3a and can internally decode Dolby TrueHD and DTS HD-MA.  What this means is they have very advanced DSPs (limited purpose computer chip) in them.  The DSPs run software just like a computer and that software had a few bugs, one of which could in theory destroy speakers under very specific conditions.  As a result just like most other modern consumer electronics it can be upgraded.  The cool thing in this story is how.  There are actually two pieces of software that run my AVR, the main firmware (operating system) and DSP firmware (drivers).  The main firmware is updated in a fairly standard way via an attached RS232 (serial) cable from a computer.  The DSP firmware however is updated through the optical digital in port from a CD player.  Yes you play a music CD (well it is made like a music CD, you wouldn't want to listen to it) and the DSP goes hey that is an update and starts loading the "music" as an upgrade.  It was quite a painless process and was quite impressive.  The bad thing about modern consumer electronics is they are so complex they have bugs.  The good thing (at least with some) is that those bugs can be fixed after you buy them for free usually.  One might say why didn't they prevent these bugs, well the main reason is there was nothing to test the DSPs with until recently since nothing fully used them.  Many companies developed toward a specification that detailed how to encode, decode and transport data.  Somewhere along they way it didn't work 100%, which is somewhat to be expected when you have nothing to test against before selling the product.  Hopefully the problems are fixed and I can enjoy my AVR without worry now.