Audio Systems: Electical Car Stereo Problem, harmon kardon, alpine stereo

Question
I installed a new Alpine stereo deck and the new Harmon Kardon IPOD connector/display into my car.  Everything was working fine for a while and then I started having problems with my car ignition.  I hooked the Harmon Kardon component directly into my car's ignition for power (this was one of the recommended ways to set it up).  It doesn't happen all the time, but sometimes (a lot more frequently now) when I try to start the car, all my power goes dead in the car.  I open and close the door firmly and the power comes back on.  Sometimes I have to do this several times for the car to finally start.  When the power goes out, everything electrical resets in my car like the clock, radio presets etc...  Do you know how I can rectify this situation on my own?  Thanks for the help.

Answer
very strange. when you say you connected it to the ignition what exactly do you mean?  You spliced the wires in the key's harness or what?  usually the wires that are in the radio harness are all you need.
Let me know exactly what you did.
What kind of car is it.