Doesnt Make Sense

[Antigenus]

I'm sure you guys are growing tired of my repeated questions, but I swear as soon as I fix one thing I have a new problem! Anyways, this one is kind of brought on myself, but it was necessary.
My factory CD player has been flakey for over 2 months now, it hardly ever comes on (yet the illumination always works) and will come on randomly and then cut out sometimes when i turn off the car and not come back on. I figured, hey this car is 14 years old, its toast and needs a new CD player. I pulled the old one out, tested the 2 power wires (one is yellow, other is red) with a meter and got the proper voltage (approx. 12v) and since I'm fairly skilled at speaker and cd player installs I dropped in my new Pioneer DEHM80MP MP3 player and 2 - 6.5" Infinity 200 Watt door speakers. The yellow (i think) is a ignition controller voltage, and only sends voltage when the ignition is turned and the red wire is constant 12volt current. The CD player turned on once i connect these 2 wires and the ground wire.
Now i was enjoying the cd player for about 14 hours until I stopped to get gas, turned the car off and then nothing (just like the old one) until I stopped at a buddy's house left and it worked. Then I tried it later, it didnt work. I got to my house, tested it again, and it was pulling 11volts out of the yellow and red with the car on, and this was tested directly in the cd harness. So no leads are bad. Could I have a knick on a wire deeper down? WTF is this problem? One thing I cant handle is listening to myself think while Im driving 45 mins to work all the time. I'm really close to hardwiring this Mother Effer to my battery terminal and putting a manual cutoff switch to turn off when I get out of the car.