Static discharge - strange effect on amp

I know there are fairly simple solutions to avoid this problem, but I'm more interested in an explanation of the phenomenon itself. I have a Linn Majik that sits on a Sound Organization welded steel rack. In the cold season here in northern US, the air gets dry, and static electricity buildup can be a nuisance. On occasion, when I've walked over to my stereo and inadvertently discharged static buildup into the rack (that is, upon touching the steel rack, not a piece of stereo equipment), the sound from my system completely cuts out. I can get the sound back by selecting another source circuit on the Majik and then switching back to the original source. (The Majik, of course, uses solid state switches.) I'm puzzled by the fact that the static discharge affects the Majik, since it is separated from the equipment rack frame by an MDF shelf and rubber feet. Of course, interconnects and speaker cables touch the frame at points -- can these act as a pathway for the discharge? And as far as what is going on in the Majik's circuitry, I have no idea but would be curious to know. As I said, I can avoid causing this problem, but I am curious to know more about it in case it might indicate anything else about the condition of my equipment.